Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

A generalized approach to x-ray data modeling for high-energy-density plasma experiments

Accurate understanding of x-ray diagnostics is crucial for both interpreting high-energy-density experiments and testing simulations through quantitative comparisons. X-ray diagnostic models are complex. Past treatments of individual x-ray diagnostics on a case-by-case basis have hindered universal diagnostic understanding. Here, we derive a general formula for modeling the absolute response of non-focusing x-ray diagnostics, such as x-ray imagers, one-dimensional space-resolved spectrometers, and x-ray power diagnostics. The present model is useful for both data modeling and data processing. It naturally accounts for the x-ray crystal broadening. The new model verifies that standard approaches for a crystal response can be good approximations, but they can underestimate the total reflectivity and overestimate spectral resolving power by more than a factor of 2 in some cases near reflectivity edge features. We also find that a frequently used, simplified-crystal-response approximation for processing spectral data can introduce an absolute error of more than an order of magnitude and the relative spectral radiance error of a factor of 3. The present model is derived with straightforward geometric arguments. It is more general and is recommended for developing a unified picture and providing consistent treatment over multiple x-ray diagnostics. Such consistency is crucial for reliable multi-objective data analyses.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

All-Order Full-Coulomb Quantum Spectral Line-Shape Calculations

Understanding how atoms interact with hot dense matter is essential for astrophysical and laboratory plasmas. Interactions in high-density plasmas broaden spectral lines, providing a rare window into interactions that govern, for example, radiation transport in stars. However, up to now, spectral line-shape theories employed at least one of three common approximations: second-order Taylor treatment of broadening operator, dipole-only interactions between atom and plasma, and classical treatment of perturbing electrons. In this Letter, we remove all three approximations simultaneously for the first time and test the importance for two applications: neutral hydrogen and highly ionized magnesium and oxygen. We found 15%-50% change in the spectral line widths, which are sufficient to impact applications including white-dwarf mass determination, stellar-opacity research, and laboratory plasma diagnostics.

Observation of ionization trends in a laboratory photoionized plasma experiment at Z

We report experimental and modeling results for the charge state distribution of laboratory photoionized neon plasmas in the first systematic study over nearly an order of magnitude range of ionization parameter ξ∝F/N_{e}. The range of ξ is achieved by flexibility in the experimental platform to adjust either the x-ray drive flux F at the sample or the electron number density N_{e} or both. Experimental measurements of photoionized plasma conditions over such a range of parameters enable a stringent test of atomic kinetics models used within codes that are applied to photoionized plasmas in the laboratory and astrophysics. From experimental transmission data, ion areal densities are extracted by spectroscopic analysis that is independent of atomic kinetics modeling. The measurements reveal the net result of the competition between photon-driven ionization and electron-driven recombination atomic processes as a function of ξ as it affects the charge state distribution. Results from radiation-hydrodynamics modeling calculations with detailed inline atomic kinetics modeling are compared with the experimental results. There is good agreement in the mean charge and overall qualitative similarities in the trends observed with ξ but significant quantitative differences in the fractional populations of individual ions.

Tauroursodeoxycholic Acid Attenuates Diet-Induced and Age-Related Peripheral Endoplasmic Reticulum Stress and Cerebral Amyloid Pathology in a Mouse Model of Alzheimer's Disease

BACKGROUND

Obesity and diabetes are well-established risk factors of Alzheimer's disease (AD). In the brains of patients with AD and model mice, diabetes-related factors have been implicated in the pathological changes of AD. However, the molecular mechanistic link between the peripheral metabolic state and AD pathophysiology have remained elusive. Endoplasmic reticulum (ER) stress is known as one of the major contributors to the metabolic abnormalities in obesity and diabetes. Interventions aimed at reducing ER stress have been shown to improve the systemic metabolic abnormalities, although their effects on the AD pathology have not been extensively studied.

OBJECTIVES

We examined whether interventions targeting ER stress attenuate the obesity/diabetes-induced Aβ accumulation in brains. We also aimed to determine whether ER stress that took place in the peripheral tissues or central nervous system was more important in the Aβ neuropathology. Furthermore, we explored if age-related metabolic abnormalities and Aβ accumulation could be suppressed by reducing ER stress.

METHODS

APP transgenic mice (A7-Tg), which exhibit Aβ accumulation in the brain, were used as a model of AD to analyze parameters of peripheral metabolic state, ER stress, and Aβ pathology in the brain. Intraperitoneal or intracerebroventricular administration of taurodeoxycholic acid (TUDCA), a chemical chaperone, was performed in high-fat diet (HFD)-fed A7-Tg mice for ~1 month, followed by analyses at 9 months of age. Mice fed a normal diet were treated with TUDCA by drinking water for 4 months and intraperitoneally for 1 month in parallel, and analyzed at 15 months of age.

RESULTS

Intraperitoneal administration of TUDCA suppressed ER stress in the peripheral tissues and ameliorated the HFD-induced obesity and insulin resistance. Concomitantly, Aβ levels in the brain were significantly reduced. In contrast, intracerebroventricular administration of TUDCA had no effect on the Aβ levels. Peripheral administration of TUDCA was also effective against the age-related obesity and insulin resistance, and markedly reduced amyloid accumulation.

CONCLUSIONS

Interventions that target peripheral ER stress might be beneficial therapeutic and prevention strategies against brain Aβ pathology associated with metabolic overload and aging.

Background measurement methods for opacity experiments conducted at the Z facility

Laboratory experiments typically test opacity models by measuring spectrally resolved transmission of a sample using bright backlight radiation. A potential problem is that any unaccounted background signal contaminating the spectrum will artificially reduce the inferred opacity. Methods developed to measure background signals in opacity experiments at the Sandia Z facility are discussed. Preliminary measurements indicate that backgrounds are 9%-11% of the backlight signal at wavelengths less than 10 Å. Background is thus a relatively modest correction for all Z opacity data published to date. Future work will determine how important background is at longer wavelengths.

Effect of Electron Capture on Spectral Line Broadening in Hot Dense Plasmas

Accurate calculation of spectral line broadening is important for many hot, dense plasma applications. However, calculated line widths have significantly underestimated measured widths for Δn=0 lines of Li-like ions, which is known as the isolated-line problem. In this Letter, scrutinization of the line-width derivation reveals that the commonly used expression neglects a potentially important contribution from electron-capture. Line-width calculations including this process are performed with two independent codes, both of which removed the discrepancies at temperatures below 10 eV. The revised calculations also suggest the remaining discrepancy scales more strongly with electron temperature than the atomic number as was previously suggested.

Systematic Study of L-Shell Opacity at Stellar Interior Temperatures

The first systematic study of opacity dependence on atomic number at stellar interior temperatures is used to evaluate discrepancies between measured and modeled iron opacity [J. E. Bailey et al., Nature (London) 517, 56 (2015)NATUAS0028-083610.1038/nature14048]. High-temperature (>180  eV) chromium and nickel opacities are measured with ±6%-10% uncertainty, using the same methods employed in the previous iron experiments. The 10%-20% experiment reproducibility demonstrates experiment reliability. The overall model-data disagreements are smaller than for iron. However, the systematic study reveals shortcomings in models for density effects, excited states, and open L-shell configurations. The 30%-45% underestimate in the modeled quasicontinuum opacity at short wavelengths was observed only from iron and only at temperature above 180 eV. Thus, either opacity theories are missing physics that has nonmonotonic dependence on the number of bound electrons or there is an experimental flaw unique to the iron measurement at temperatures above 180 eV.

Experimental Validation of Low-Z Ion-Stopping Formalisms around the Bragg Peak in High-Energy-Density Plasmas

We report on the first accurate validation of low-Z ion-stopping formalisms in the regime ranging from low-velocity ion stopping-through the Bragg peak-to high-velocity ion stopping in well-characterized high-energy-density plasmas. These measurements were executed at electron temperatures and number densities in the range of 1.4-2.8 keV and 4×10^{23}-8×10^{23}  cm^{-3}, respectively. For these conditions, it is experimentally demonstrated that the Brown-Preston-Singleton formalism provides a better description of the ion stopping than other formalisms around the Bragg peak, except for the ion stopping at v_{i}∼0.3v_{th}, where the Brown-Preston-Singleton formalism significantly underpredicts the observation. It is postulated that the inclusion of nuclear-elastic scattering, and possibly coupled modes of the plasma ions, in the modeling of the ion-ion interaction may explain the discrepancy of ∼20% at this velocity, which would have an impact on our understanding of the alpha energy deposition and heating of the fuel ions, and thus reduce the ignition threshold in an ignition experiment.

Benchmark Experiment for Photoionized Plasma Emission from Accretion-Powered X-Ray Sources

The interpretation of x-ray spectra emerging from x-ray binaries and active galactic nuclei accreted plasmas relies on complex physical models for radiation generation and transport in photoionized plasmas. These models have not been sufficiently experimentally validated. We have developed a highly reproducible benchmark experiment to study spectrum formation from a photoionized silicon plasma in a regime comparable to astrophysical plasmas. Ionization predictions are higher than inferred from measured absorption spectra. Self-emission measured at adjustable column densities tests radiation transport effects, demonstrating that the resonant Auger destruction assumption used to interpret black hole accretion spectra is inaccurate.

Numerical investigations of potential systematic uncertainties in iron opacity measurements at solar interior temperatures

Iron opacity calculations presently disagree with measurements at an electron temperature of ∼180-195 eV and an electron density of (2-4)×10^{22}cm^{-3}, conditions similar to those at the base of the solar convection zone. The measurements use x rays to volumetrically heat a thin iron sample that is tamped with low-Z materials. The opacity is inferred from spectrally resolved x-ray transmission measurements. Plasma self-emission, tamper attenuation, and temporal and spatial gradients can all potentially cause systematic errors in the measured opacity spectra. In this article we quantitatively evaluate these potential errors with numerical investigations. The analysis exploits computer simulations that were previously found to reproduce the experimentally measured plasma conditions. The simulations, combined with a spectral synthesis model, enable evaluations of individual and combined potential errors in order to estimate their potential effects on the opacity measurement. The results show that the errors considered here do not account for the previously observed model-data discrepancies.

Osteogenic Potential of Adipose-Derived Macrospheroids Cocultured with CD11b+ Monocytes

PURPOSE

Among potential cell-based therapies, adipose-derived stem cells (ASCs) have been proposed as a promising source of stem cells for tissue regeneration. Although many recent clinical trials have investigated the use of adipose tissue or ASCs in transplantation, analysis of the microstructures of outgrowing macrosized spheroids (macrospheroids) or three-dimensional coculture of ASC spheroids and monocyte/macrophage lineages has not been performed. The aim of this study was to analyze the microstructures of murine-derived ASC macrospheroids and the growth and osteogenic potential of these macrospheroids in a three-dimensional environment and after calcification induction by coculture with monocytes.

MATERIALS AND METHODS

The histologic structures of murine-derived ASC macrospheroids and the expression of marker genes for multipotency within these macrospheroids were analyzed by hematoxylin and eosin staining and in situ hybridization. ASC macrospheroid microstructures were observed by transmission electron microscopy, and cell proliferation in the spheroids was analyzed. Additionally, the growth and osteogenic potential of these macrospheroids were assessed in two-dimensional and three-dimensional environments and after calcification induction by coculture with monocytes.

RESULTS

The expression of Oct3/4, Nanog, and Sox2 was detected even in the deep zone of spheroids, although higher expression was observed at the surface. Cell proliferation was detected within the spheroid centers. Observation of spheroid microstructure revealed extracellular matrix production within the spheroid architecture. Transplantation of a spheroid on the hydroxyapatite disc resulted in three-dimensional cell growth, filling the disc. Coculture of the spheroids with monocytes led to the formation of many osteoclast-like, multinucleated cells, and calcification was observed after 3 weeks of coculture.

CONCLUSION

ASC spheroids exhibited high capacity for dynamic three-dimensional growth and osteogenic differentiation. Furthermore, ASC spheroids promoted monocyte differentiation into osteoclast-like cells, which may enhance the osteogenic potential of ASC spheroids.

Laser propagation measurements in long-scale-length underdense plasmas relevant to magnetized liner inertial fusion

We report experimental results and simulations showing efficient laser energy coupling into plasmas at conditions relevant to the magnetized liner inertial fusion (MagLIF) concept. In MagLIF, to limit convergence and increase the hydrodynamic stability of the implosion, the fuel must be efficiently preheated. To determine the efficiency and physics of preheating by a laser, an Ar plasma with n_{e}/n_{crit}∼0.04 is irradiated by a multi-ns, multi-kJ, 0.35-μm, phase-plate-smoothed laser at spot-averaged intensities ranging from 1.0×10^{14} to 2.5×10^{14}W/cm^{2} and pulse widths from 2 to 10 ns. Time-resolved x-ray images of the laser-heated plasma are compared to two-dimensional radiation-hydrodynamic simulations that show agreement with the propagating emission front, a comparison that constrains laser energy deposition to the plasma. The experiments show that long-pulse, modest-intensity (I=1.5×10^{14}W/cm^{2}) beams can efficiently couple energy (∼82% of the incident energy) to MagLIF-relevant long-length (9.5 mm) underdense plasmas. The demonstrated heating efficiency is significantly higher than is thought to have been achieved in early integrated MagLIF experiments [A. B. Sefkow et al., Phys. Plasmas 21, 072711 (2014)10.1063/1.4890298].

Calibrated simulations of Z opacity experiments that reproduce the experimentally measured plasma conditions

Recently, frequency-resolved iron opacity measurements at electron temperatures of 170-200 eV and electron densities of (0.7-4.0)×10(22)cm(-3) revealed a 30-400% disagreement with the calculated opacities [J. E. Bailey et al., Nature (London) 517, 56 (2015)]. The discrepancies have a high impact on astrophysics, atomic physics, and high-energy density physics, and it is important to verify our understanding of the experimental platform with simulations. Reliable simulations are challenging because the temporal and spatial evolution of the source radiation and of the sample plasma are both complex and incompletely diagnosed. In this article, we describe simulations that reproduce the measured temperature and density in recent iron opacity experiments performed at the Sandia National Laboratories Z facility. The time-dependent spectral irradiance at the sample is estimated using the measured time- and space-dependent source radiation distribution, in situ source-to-sample distance measurements, and a three-dimensional (3D) view-factor code. The inferred spectral irradiance is used to drive 1D sample radiation hydrodynamics simulations. The images recorded by slit-imaged space-resolved spectrometers are modeled by solving radiation transport of the source radiation through the sample. We find that the same drive radiation time history successfully reproduces the measured plasma conditions for eight different opacity experiments. These results provide a quantitative physical explanation for the observed dependence of both temperature and density on the sample configuration. Simulated spectral images for the experiments without the FeMg sample show quantitative agreement with the measured spectral images. The agreement in spectral profile, spatial profile, and brightness provides further confidence in our understanding of the backlight-radiation time history and image formation. These simulations bridge the static-uniform picture of the data interpretation and the dynamic-gradient reality of the experiments, and they will allow us to quantitatively assess the impact of effects neglected in the data interpretation.

Understanding reliability and some limitations of the images and spectra reconstructed from a multi-monochromatic x-ray imager

Temperature and density asymmetry diagnosis is critical to advance inertial confinement fusion (ICF) science. A multi-monochromatic x-ray imager (MMI) is an attractive diagnostic for this purpose. The MMI records the spectral signature from an ICF implosion core with time resolution, 2-D space resolution, and spectral resolution. While narrow-band images and 2-D space-resolved spectra from the MMI data constrain temperature and density spatial structure of the core, the accuracy of the images and spectra depends not only on the quality of the MMI data but also on the reliability of the post-processing tools. Here, we synthetically quantify the accuracy of images and spectra reconstructed from MMI data. Errors in the reconstructed images are less than a few percent when the space-resolution effect is applied to the modeled images. The errors in the reconstructed 2-D space-resolved spectra are also less than a few percent except those for the peripheral regions. Spectra reconstructed for the peripheral regions have slightly but systematically lower intensities by ∼6% due to the instrumental spatial-resolution effects. However, this does not alter the relative line ratios and widths and thus does not affect the temperature and density diagnostics. We also investigate the impact of the pinhole size variation on the extracted images and spectra. A 10% pinhole size variation could introduce spatial bias to the images and spectra of ∼10%. A correction algorithm is developed, and it successfully reduces the errors to a few percent. It is desirable to perform similar synthetic investigations to fully understand the reliability and limitations of each MMI application.

Parallax diagnostics of radiation source geometric dilution for iron opacity experiments

Experimental tests are in progress to evaluate the accuracy of the modeled iron opacity at solar interior conditions [J. E. Bailey et al., Phys. Plasmas 16, 058101 (2009)]. The iron sample is placed on top of the Sandia National Laboratories z-pinch dynamic hohlraum (ZPDH) radiation source. The samples are heated to 150-200 eV electron temperatures and 7× 10(21)-4× 10(22) cm(-3) electron densities by the ZPDH radiation and backlit at its stagnation [T. Nagayama et al., Phys. Plasmas 21, 056502 (2014)]. The backlighter attenuated by the heated sample plasma is measured by four spectrometers along ±9° with respect to the z-pinch axis to infer the sample iron opacity. Here, we describe measurements of the source-to-sample distance that exploit the parallax of spectrometers that view the half-moon-shaped sample from ±9°. The measured sample temperature decreases with increased source-to-sample distance. This distance must be taken into account for understanding the sample heating.

Expression of ZNF396 in basal cell carcinoma

Zfp191 represses differentiation and keeps various cells in the stem/progenitor stage. Here, we report that a Zfp191 homolog protein, ZNF396, is expressed in basal cell carcinoma (BCC) and possibly represses the expression of a Notch system effector molecule, Hes1 (hairy and enhancer of split-1), and prevents BCC cells from undergoing Notch-mediated squamous cell differentiation. ZNF396 immunoreactivity was found in the nucleus of 35 of 38 cutaneous BCC and 4 of 74 squamous cell carcinoma tissue specimens. In non-tumorous epidermal tissues, ZNF396 immunoreactivity was restricted in basal cells. siRNA-mediated silencing of ZNF396 induced the expression of Notch2, Hes1, and involucrin in cultured BCC cells. Finally, we found that siRNA-mediated silencing of ZNF396 gene inhibited the proliferation of TE354.T basal cell carcinoma cells. ZNF396 might repress Notch-Hes1 signaling axis and prevent tumor cells from undergoing squamous differentiation in BCC.

Pathobiological properties of the ubiquitin ligase Nedd4L in melanoma

A recent global gene expression profiling study unexpectedly showed that activated oncogenic NRAS may recruit neural precursor cell expressed, developmentally downregulated 4L (Nedd4L; a human homologue of Nedd4-2) in cultured melanoma cells. However, whether Nedd4L was expressed in melanoma tissues or participated in melanoma carcinogenesis remains to be clarified. Here, we investigated the expression status of Nedd4L in human melanocytes, benign nevi and melanoma tissue specimens and subsequently attempted to determine the role of Nedd4L in melanoma cell growth. Immunohistochemical staining revealed that Nedd4L was not present in any non-tumorous melanocytes or in 18 benign nevi tissues, but it was detected in 34 of 79 cutaneous melanomas and 9 of 32 nodal metastatic melanomas. Downregulation of Nedd4L significantly reduced the growth of cultured G361 melanoma cells in vitro. Moreover, exogenous Nedd4L expression significantly promoted the growth of A2058 melanoma cells in vivo in a xenograft assay. The present findings indicate that Nedd4L expression may be increased to facilitate tumour growth in many melanomas.

FGF18 accelerates osteoblast differentiation by upregulating Bmp2 expression

Fibroblast growth factor (FGF) signaling is involved in skeletal development. Among total 22 FGFs, it is suggested that FGF18 functions in promotion of osteoblast differentiation. In order to elucidate the mechanism of FGF18-dependent acceleration of osteogenesis, we implanted rhFGF18 soaked beads over mouse fetal coronal sutures using ex-utero surgery. The coronal suture area comprises the peripheries of the developing frontal and parietal bones, separated by the sutural mesenchyme. rhFGF18 accelerated osteogenesis by promoting connection of the frontal and parietal bone domains, resulting in elimination of the sutural mesenchyme. Expression of Fgf receptors, Fgfr1, -2 and -3 involved in skeletal development, was maintained or upregulated in the developing bone domains, consistent with enhanced osteogenesis. Bone morphogenetic protein (Bmp) 2 was specifically upregulated in the skeletogenic layer and the application of Bmp antagonist, rmNoggin, inhibited rhFGF18-dependent upregulation of osteoblast markers. These results suggest that FGF18 accelerates osteogenesis by upregulation of Bmp2 as well as maintenance or upregulation of Fgfr1, -2 and -3 expression in osteoblasts.

Investigation of iron opacity experiment plasma gradients with synthetic data analyses

Experiments have been performed at Sandia National Laboratories Z-facility to validate iron opacity models relevant to the solar convection/radiation zone boundary. Sample conditions were measured by mixing Mg with the Fe and using Mg K-shell line transmission spectra, assuming that the plasma was uniform. We develop a spectral model that accounts for hypothetical gradients, and compute synthetic spectra to quantitatively evaluate the plasma gradient size that can be diagnosed. Two sample designs are investigated, assuming linear temperature and density gradients. First, Mg uniformly mixed with Fe enables temperature gradients greater than 10% to be detected. The second design uses Mg mixed into one side and Al mixed into the other side of the sample in an attempt to more accurately infer the sample gradient. Both temperature and density gradients as small as a few percent can be detected with this design. Experiments have successfully recorded spectra with the second design. In future research, the spectral model will be used to place bounds on gradients that exist in Z opacity experiments.

A WWOX-binding molecule, transmembrane protein 207, is related to the invasiveness of gastric signet-ring cell carcinoma

Using the PCR-based subtractive messenger RNA hybridization assay described in this paper, we isolated a hitherto uncharacterized gene, transmembrane protein 207 (TMEM207), which was selectively expressed in collagen gel-invading cultured signet-ring cell carcinoma KATO-III cells. TMEM207 has a C-terminal proline-rich PPxY motif, which binds to the WW domain-containing oxidoreductase, WWOX. Enforced expression of TMEM207 significantly increased Matrigel invasion activity of KATO-III cells in vitro without affecting cell growth. In contrast, expression of TMEM207 with mutations in the PPxY motif did not significantly increase Matrigel invasion activity of KATO-III cells. Immunohistochemical staining showed that TMEM207 was strongly expressed in 7 of 30 gastric signet-ring cell carcinoma tissue specimens. Notably, TMEM207 expression was associated with the depth of cancer invasion and the presence of lymph node metastasis. The results of co-immunoprecipitation followed by western immunoblotting showed that TMEM207 is bound to WWOX in a PPxY motif-dependent manner. Small interfering RNA-mediated downregulation of WWOX also significantly increased Matrigel invasion activity of KATO-III cells. Notably, exogenous expression of TMEM207 impaired the WWOX-mediated repression of Matrigel invasion activity of another cultured signet-ring cell carcinoma cell line, NUGC-4 cells. Recent studies have highlighted the fact that WWOX acts as a tumor suppressor factor in various malignant tumors, including gastric cancer. On the basis of these findings and the results of the present study, we think that overexpression of TMEM207 may facilitate invasive activity and metastasis of gastric signet-ring cell carcinoma, which possibly occur through binding to WWOX and attenuation of its function.

Expression of a secretory protein C1qTNF6, a C1qTNF family member, in hepatocellular carcinoma

Background: Recent studies have revealed that the adiponectin-associated protein belonging to the C1qTNF family mediates various biological processes. However, the pathobiological property of C1qTNF6 in carcinogenesis remains unclear. Here, we investigated the expression status of C1qTNF6 in human hepatocellular carcinomas and subsequently attempted to determine the role of C1qTNF6 in tumor neovascularization. Methods: Immunohistochemical staining was performed to evaluate the expression of C1qTNF6 in hepatocellular carcinoma tissue specimens. Various eukaryotic recombinant C1qTNF6 proteins were prepared to ask whether C1qTNF6 could activate Akt pathway in human liver sinusoidal microvascular endothelial cells. Xenograft assay was carried out to know the effect of C1qTNF6 on tumor neovascularization. Results: C1qTNF6 was not immunohistochemically detected in any non-cancerous liver tissues but was detected in 21 of 30 hepatocellular carcinoma tissue specimens. C1qTNF6 was not uniformly distributed but rather focally localized in hepatocellular carcinoma cells. Interestingly, it was also localized on the tumor endothelial cells, which were in close proximity of C1qTNF6-expressing hepatocellular carcinoma cells. Eukaryotic recombinant C1qTNF6 increased the level of active phosphorylated Akt molecules in cultured vascular endothelial cells via its C-terminal C1q domain. In the xenograft assay, enforced expression of C1qTNF6 markedly reduced the central hypovascular necrosis areas of the transplanted HepG2 hepatocellular carcinoma cells. Conclusion: These results indicate that C1qTNF6 is overexpressed and possibly contributes to tumor angiogenesis by activating the Akt pathway in many hepatocellular carcinomas.

Measurements of core and compressed-shell temperature and density conditions in thick-wall target implosions at the OMEGA laser facility

A spectroscopic method is discussed to measure core and compressed-shell conditions in thick-wall plastic-shell implosions filled with deuterium and a tracer amount of argon. Simultaneous observation over a broad photon energy range of the argon line emission and the attenuation and self-emission effects of the compressed shell confining the core yields enough information to extract average temperature and density conditions in both core and compressed shell. The spectroscopic analysis also provides an estimate of the target areal density which is an important characteristic of inertial confinement fusion implosions.

Nedd4L modulates the transcription of metalloproteinase-1 and -13 genes to increase the invasive activity of gallbladder cancer

The aim of this study was to examine whether Nedd4L (neural precursor cell expressed, developmentally down-regulated 4-like) participated in gallbladder carcinogenesis. We first immunohistochemically examined the expression of Nedd4L in various gallbladder tissue specimens. Weak immunoreactivity to Nedd4L-specific antibody was observed in normal or dysplastic epithelial cells. Cancer cells in non-invasive regions exhibited little immunoreactivity, whereas strong immunostaining was found in cytoplasm of many invasive cancers, especially at cancer invasive front with desmoplastic reaction. Notably, siRNA-mediated silencing of the Nedd4L gene significantly decreased the Matrigel-invasion activity and collagen invasion activity of cultured gallbladder cancer cells, without affecting the cell growth. The subtractive mRNA hybridization followed by RT-PCR and immunoblotting revealed that down-regulation of Nedd4L significantly decreased the expression of collagenases, matrix metalloproteinase (MMP)-1 and -13, in gallbladder cancer cells. Finally, immunohistochemical staining showed that many Nedd4L-expressing invasive gallbladder cancer cells co-expressed MMP-1 and MMP-13. These results indicated that over-expression of Nedd4L might lead to gallbladder cancer invasion by regulating the transcription of the MMP-1 and MMP-13 genes.

Spectroscopic modeling of an argon-doped shock-ignition implosion

We present results from the spectral postprocessing of a one-dimensional hydrodynamic simulation of an argon-doped, warm-shell shock-ignition implosion with a detailed atomic and radiation physics model. The argon tracer is added to the deuterium filling in the core for diagnostic purposes. Spectral features in the emergent intensity distribution in the photon energy range of the argon K-shell spectrum that have potential for diagnostic application are discussed.

T-cadherin modulates tumor-associated molecules in gallbladder cancer cells

T-cadherin is believed to act against carcinogenesis in various tissues; however, its tumor-suppressor mechanism remains largely unclear. Using subtractive mRNA hybridization and immunoblotting, the present study identified several cancer-associated molecules whose expression was modified by T-cadherin in gallbladder cancer cells. Restoration of T-cadherin decreased the expression of Akt3 and phosphorylated Akt molecules. SET7/9, which stabilizes chromatin-bound p53, was downregulated by silencing of T-cadherin but was not regulated by the expression of T-cadherin. These finding suggest that T-cadherin might inhibit tumor progression through multiple pathways, including the Akt and SET7/9-p53 pathways.

Comparison of genetic-algorithm and emissivity-ratio analyses of image data from OMEGA implosion cores

Detailed analysis of x-ray narrow-band images from argon-doped deuterium-filled inertial confinement fusion implosion experiments yields information about the temperature spatial structure in the core at the collapse of the implosion. We discuss the analysis of direct-drive implosion experiments at OMEGA, in which multiple narrow-band images were recorded with a multimonochromatic x-ray imaging instrument. The temperature spatial structure is investigated by using the sensitivity of the Ly beta/He beta line emissivity ratio to the temperature. Three analysis methods that consider the argon He beta and Ly beta image data are discussed and the results compared. The methods are based on a ratio of image intensities, ratio of Abel-inverted emissivities, and a search and reconstruction technique driven by a Pareto genetic algorithm.

Analysis of time-resolved argon line spectra from OMEGA direct-drive implosions

We discuss the observation and data analysis of argon K-shell line spectra from argon-doped deuterium-filled OMEGA direct-drive implosion cores based on data recorded with two streaked crystal spectrometers. The targets were 870 microm in diameter, 27 microm wall thickness plastic shells filled with 20 atm of deuterium gas, and a tracer amount of argon for diagnostic purposes. The argon K-shell line spectrum is primarily emitted at the collapse of the implosion and its analysis provides a spectroscopic diagnostic of the core implosion conditions. The observed spectra includes the He alpha, Ly alpha, He beta, He gamma, Ly beta, and Ly gamma line emissions and their associated He- and Li-like satellites thus covering a broad photon energy range from 3100 to 4200 eV with a spectral resolution power of approximately 500. The data analysis relies on detailed atomic and spectral models that take into account nonequilibrium collisional-radiative atomic kinetics, Stark-broadened line shapes, and radiation transport calculations.

Effects of spaceflight on postnatal development of arterial baroreceptor reflex in rats

AIM

It has been reported that spaceflight attenuates the arterial baroreceptor reflex. As this reflex function changes dramatically during postnatal development, we hypothesized that space flight depresses the developmental changes of the reflex system. To test this hypothesis, we evaluated the baroreceptor reflex function in rats, which were exposed to a microgravity environment on a space shuttle 9-25 days after birth.

METHODS

Baroreceptor reflex sensitivity and the afferent sensitivity were evaluated by measuring heart rate (HR) and aortic nerve activity (ANA) changes in response to an increase in mean arterial pressure (MBP) derived by phenylephrine injection (20-50 microg kg(-1)) under urethane-anaesthesia.

RESULTS

Baroreceptor reflex sensitivity (% change of HR/% change of MBP) was lower in the flight group (FLT: -0.19 +/- 0.04, n = 4) than either the asynchronous ground control group (AGC: -0.47 +/- 0.06, n = 6, P < 0.01) or the vivarium group (VIV: -0.41 +/- 0.07, n = 6, P < 0.05). This was similar to the differences of the afferent sensitivity (% change of ANA/% change of MBP) between FLT (2.07 +/- 0.30) and the control groups (AGC: 2.71 +/- 0.22, n.s.; VIV: 3.00 +/- 0.32, P < 0.05). At the end of 30 days of recovery under normal gravity conditions, however, there were no significant group differences in these parameters. conclusion: These results suggest that the space environment attenuates the postnatal development of the arterial baroreceptor reflex function in rats, which may be partially because of a depression of the postnatal development of the baroreceptor afferents. These functional alterations, however, recover to their normal level on re-exposure to the Earth's gravity.

Spaceflight alters the fiber composition of the aortic nerve in the developing rat

Hydrostatic pressure gradients due to the gravitational force in blood vessels disappear under conditions of microgravity during spaceflight, and the ability of the baroreceptor reflex to control arterial pressure and blood distribution may be altered. We hypothesized, on the basis of the results obtained in our previous experiments using the head-down tilt method in rats and rabbits, that the range of increase in arterial pressure caused by animal behavior narrows under conditions of microgravity, affecting the development of high-threshold unmyelinated fibers in the rat aortic nerve which sends signals from baroreceptors located in the aortic wall to the reflex center. We verified this hypothesis using 9-day-old rat neonates housed with their dams for 16 days on the space shuttle Columbia in outer space (STS-90, Neurolab Mission). Age-matched neonatal rats with the dams remained on the ground as controls. After breeding was carried out in the three experimental groups (FLT, spaceflight; AGC, asynchronous ground control; VIV, vivarium ground control), specimens of the 25-day-old rats were excised and five left aortic nerves in each group were examined by electron microscopy. The number of aortic unmyelinated fibers was significantly less in the FLT group than in each ground control (mean+/-S.D.; 139+/-37 in the FLT, 207+/-36 in the AGC, 283+/-121 in the VIV; P<0.05), which may be related to the weakness of the baroreceptor reflex under conditions of microgravity in space. This result may contribute to understanding of the several cardiovascular issues which occur under microgravity and after reexposure to gravity in human.

Effects of sevoflurane on autonomic nerve activities controlling cardiovascular functions in rats

Effects of different inspiratory concentrations of sevoflurane (fluorometyl-1,1,1,3,3,3,-hexafluoro-2-propylether) on blood pressure, heart rate and efferent activities of cardiac sympathetic, cardiac parasympathetic and renal sympathetic nerves were examined using rats either under the resting condition or during noxious mechanical stimulation of a hindpaw. Under the resting condition, an increase in the inspiratory concentration of sevoflurane from 2.1% to 4.2% gradually caused a decrease in blood pressure and heart rate. With the increase in the sevoflurane concentration, cardiac sympathetic nerve activity decreased, whereas renal sympathetic nerve and cardiac parasympathetic nerve activities did not change significantly. When noxious mechanical stimulation was applied to a hind-paw by pinching, blood pressure and heart rate, renal sympathetic and cardiac sympathetic nerve activities all increased at the 2.1% concentration of sevoflurane. The responses of these parameters were attenuated at the 3.1% concentration of sevoflurane and almost disappeared at the 4.2% concentration. Cardiac parasympathetic nerve activity did not change significantly during the pinching stimulation throughout the 2.1-4.2% concentration increase.

Synaptic interactions between nonspiking local interneurones in the terminal abdominal ganglion of the crayfish

Nonspiking local interneurones are the important premotor elements in arthropod motor control systems. We have analyzed the synaptic interactions between nonspiking interneurones in the crayfish terminal (6th) abdominal ganglion using simultaneous intracellular recordings. Only 15% of nonspiking interneurones formed bi-directional excitatory connections. In 77% of connections, however, the nonspiking interneurones showed a one-way inhibitory interaction. In these cases, the presynaptic nonspiking interneurones received excitatory synaptic inputs from the sensory afferents innervating hairs on the surface of the uropods and the postsynaptic nonspiking interneurones received inhibitory synaptic inputs that were partly mediated by the inputs to the presynaptic nonspiking interneurones. The membrane hyperpolarization of the postsynaptic nonspiking interneurones mediated by the presynaptic nonspiking interneurones was reduced in amplitude when the hyperpolarizing current was injected into the postsynaptic interneurones, or when the external bathing solution was replaced with one containing low calcium and high magnesium concentrations. The role of these interactions in the circuits controlling the movements of the terminal appendages is discussed.

A case of germinoma in the septum pellucidum manifesting as amnesia and hemiparesis

BACKGROUND

We report a rare case of germinoma mainly located in the septum pellucidum.

CASE DESCRIPTION

A 19-year-old man presented with germinoma located in the septum pellucidum manifesting as amnesia and right hemiparesis. Magnetic resonance imaging demonstrated a heterogeneously enhanced mass in the septum pellucidum and abnormal T2-weighted signals in the left basal ganglia. An anterior transcallosal approach was performed to remove the mass in the septum pellucidum. The histological diagnosis was germinoma. Radiotherapy and chemotherapy were given. He was discharged with slight amnesia and right hemipareis.

INTERPRETATION

Intracranial germinoma can arise from the septum pellucidum.

Direct chemically mediated synaptic transmission from mechanosensory afferents contributes to habituation of crayfish lateral giant escape reaction

The neural mechanism of habituation of the crayfish lateral giant-mediated escape reaction was analyzed electrophysiologically and pharmacologically. Upon repeated stimulation of tailfan afferents (at 0.2-1 Hz) lateral giant showed rapid habituation and failed to spike. Upon low-intensity sensory stimulation, the lateral giant responded with two subthreshold excitatory post-synaptic potentials, the alpha and beta components. A third component, the alpha' component, was discriminated at the boundary of excitatory post-synaptic potentials between the late alpha and early beta components with stimulation just subthreshold or suprathreshold to evoke lateral giant spikes. This alpha' component increased in amplitude with hyperpolarizing current injected into the lateral giants, although the amplitude of both the alpha and beta components remained constant. Furthermore, bath application of the nicotinic antagonist, d-tubocurarine caused a rapid reduction in the amplitude of the alpha' component while the amplitude of the beta component was reduced gradually and that of the alpha component remained unchanged. Single-hair stimulation indicated that some sensory afferents made direct connections with the lateral giants mediated by chemical synapses and form the potential of alpha' component of the lateral giants. Since lateral giant inactivation was associated with a reduction of excitatory post-synaptic potential amplitude of the alpha' component, connection from these afferents could contribute, at least in part, to lateral giant habituation.

Foreign workers recruiting policies in Japan

"This article presents the basic characteristics of the foreign workers recruiting policy in Japan, which consists [of] barring entry to unskilled workers, and confronts it with the actual tolerance for a large number of illegal unskilled workers. After a historical overview of the reasons for the current policy, the article examines elements which reveal that a seclusionist policy is based on mistaken assumptions and reviews policy options to deal with the issue of illegal migration."

Lateral giant fibre activation of exopodite motor neurones in the crayfish tailfan

The uropods of decapod crustaceans play a major role in the production of thrust during escape swimming. Here we analyse the output connections of a pair of giant interneurones, that mediate and co-ordinate swimming tail flips, on motor neurones that control the exopodite muscles of the uropods. The lateral giants make short latency output connections with phasic uropod motor neurones, including the productor, the lateral abductor and adductor exopodite motor neurones that we have identified both physiologically and anatomically. On the other hand, tonic motor neurones, including the ventral abductor and reductor exopodite motor neurones, receive no input from the lateral giants. We show that there is no simple reciprocal activation of the phasic opener (lateral abductor) and closer (adductor) motor neurones of the exopodite, but instead both phasic motor neurones are activated in parallel with the productor motor neurone during a tail flip. Our results show that the neuronal pathways activating the tonic and phasic motor neurones of the exopodite are apparently independent, with phasic motor neurones being activated during escape movements and tonic motor neurones being activated during slow postural movements.

Fas (CD95) may mediate delayed cell death in hippocampal CA1 sector after global cerebral ischemia

Cell death-regulatory genes like caspases and bcl-2 family genes are involved in delayed cell death in the CA1 sector of hippocampus after global cerebral ischemia, but little is known about the mechanisms that trigger their expression. The authors found that expression of Fas and Fas-ligand messenger ribonucleic acid and protein was induced in vulnerable CA1 neurons at 24 and 72 hours after global ischemia. Fas-associating protein with a novel death domain (FADD) also was upregulated and immunoprecipitated and co-localized with Fas. Caspase-10 was activated and interacted with FADD protein to an increasing extent as the duration of ischemia increased. Moreover, caspase-10 co-localized with both FADD and caspase-3. These findings suggest that Fas-mediated death signaling may play an important role in signaling hippocampal neuronal death in CA1 after global cerebral ischemia.

[A case of asymptomatic urachal cyst in autopsy--histopathological study of urachal cyst and review of the literature of 99 cases during a 10 year period in Japan]

Disorders of urachal remnants are common. While urachal cysts are usually asymptomatic, infection may mimic a variety of acute abdomen. Here we report a very rare case of urachal cyst that protruded in the urinary bladder cavity and among 99 accumulated cases, only 4 cases have been reported similar to this case characterized by intravesical development from 1990 to 1999. An uninfected urachal cyst was found in a 79-year-old male who had died of bile duct carcinoma. The cyst showed ovoid protrusion into urinary bladder cavity from the dome (3.5 x 2.0 x 2.0 cm in size). Histopathologically, the cyst wall was thin and consisted of fibrous connective tissue with muscular tissue and peripheral nerve, and lined by cuboidal epithelium but no inflammatory cells could be seen. Urachal cysts occur in both sexes are affected with equal frequency, and frequently occur in a younger population. In clinical symptoms the umbilical manifestations are predominant in patients younger than 30 years old, while the bladder manifestations are predominant in those older than 30.