Consider connecting randomly individuals and imagine a law that imposes every new connection must at least involve one individual belonging to g fraction of the most disconnected population an individual being the more disconnected, the smaller the cluster of connected individuals it belongs to. Here we show that this simple strategy to improve connection exhibits a phase transition never described before, namely a hybrid phase transition with continuously varying exponents. A hybrid phase transition includes properties of both continuous and discontinuous phase transitions. Using the generating function method we evaluate the cluster size distribution of the restricted ErdősRényi model and obtain an analytic expression for the dependence of its critical exponent on g. We also obtain a susceptibility exhibiting asymmetric criticality, i.e. diverging with different exponents above and below the transition point.

Nanometer-scale imaging techniques using only a single shot of ultrafast x- ray pulse are becoming increasingly important because of their potential application in the real-time investigations of nanomaterials. X-ray lasers have a great potential to achieve single-shot nano-imaging due to their coherence and high flux. Here, we will report on single-shot Fourier Transform hologram using Ni-like Ag x-ray laser driven by a single-profiled pumping pulse. We achieved lensless Fourier transform holograms with a single pulse of x-ray laser and the reconstructed image has a minimum resolution of 87 nm.

The characteristics of high energy protons generated from thin carbon-proton mixture targets via circularly polarized intense laser pulses are investigated using two-dimensional particle-in-cell simulations. It is found that the density ratio n between protons and carbon ions plays a key role in determining the acceleration dynamics. For low n values, the protons are mainly accelerated by the radiation pressure acceleration mechanism, resulting in a quasi-monoenergetic energy spectrum. The radiation pressure acceleration mechanism is enhanced by the directed-Coulomb-explosion of carbon ions which gives a high proton maximum energy, though a large energy spread, for high n values. From a proton acceleration point of view, the role of heavy ions is very important. The fact that the proton energy spectrum is controllable based on the target composition is especially useful in real experimental environments.

Laser-driven plasma accelerators are gaining much attention by the advanced accelerator community due to the potential these accelerators hold in miniaturizing future high-energy and medium-energy machines. In the laser wakefield accelerator (LWFA), the ponderomotive force of an ultrashort high-intensity laser pulse excites a longitudinal plasma wave or bubble. Due to huge charge separation, electric fields created in the plasma bubble can be several orders of magnitude higher than those available in conventional microwave and RF-based accelerator facilities, which are limited (up to similar to 100 MV/m) by material breakdown. Therefore, if an electron bunch is injected into the bubble in phase with its field, it will gain relativistic energies within an extremely short distance. Here, in the LWFA, we show the generation of high-quality and high-energy electron beams tip to the GeV-class within a few millimeters of gas-jet plasmas irradiated by tens-of- terawatt ultrashort laser pulses. Thus, we realize approximately four orders of magnitude acceleration gradients, higher than available by conventional technology. As a practical application of the stable high-energy electron beam generation, we are planning on injecting the electron beams into a few-meter-long conventional undulator in order to realize compact X-ray synchrotron (immediate) and Ree Electron Laser (future) light sources. Stable laser-driven electron beam and radiation devices will surely open a, new era in science, medicine, and technology and will benefit a larger number of users in those fields.

Background: The outcome of older osteosarcoma patients with multi-disciplinary management has not been clearly defined.Methods: We conducted a cohort (n = 375) and a case-control (n = 78) study on 26 older age patients (40-60 years) with localized osteosarcoma of extremity. In the case control study, controls were matched for location and initial tumor volume.Results: Compared to 349 younger patients, older age patients showed an osteolytic pattern on plain radiographs (P = 0.05), fibroblastic subtype (P <0.01), and poor histologic response (P = 0.03). Multivariate analysis revealed that a large absolute tumor volume (P <0.01), a tumor location in the proximal humerus (P = 0.02), and a poor histologic response to preoperative chemotherapy (P < 0.01) independently predicted poorer metastasis-free survival. However, an older age showed marginal significance (P = 0.09). A case control study showed a higher proportion of the fibroblastic subtype and poor histologic response in the case group. Five-year metastasis-free survival rates for the 26 cases and 52 controls were 40.1 +/- 10.1% and 61.5 +/- 6.8%, respectively (P = 0.02).Conclusions: Older age osteosarcoma patients showed an unfavorable histologic response to chemotherapy and lower survival than younger patients. Nevertheless, a further larger-scale study is required to confirm our observations. (C) 2010 Elsevier Ltd. All rights reserved.

Using diffuse optical tomography we have imaged early vascular responses to anti-angiogenic treatments in a small animal tumor model. Images acquired from 1 to 7 days after drug administration show measurable changes in hemoglobin concentration. There are observable differences between mice treated with anti-angiogenic drugs and mice that receive a placebo treatment.

Cell cycle controls ensure that DNA replication (S phase) follows mitosis resulting in two precise copies of the genome. A failure of the control mechanisms can result in multiple rounds of DNA replication without cell division. In endoreplication, cells with replicated genomes bypass mitosis, then replicate their DNA again, resulting in polyploidy. Endoreplication from G2 phase lacks all hallmarks of mitosis. Using synchronized cells, we show that the c-Jun N-terminal kinase (JNK) inhibitor, SP600125, prevents the entry of cells into mitosis and leads to endoreplication of DNA from G2 phase. We show that cells proceed from G2 phase to replicate their DNA in the absence of mitosis. This effect of SP600125 is independent of its suppression of JNK activity. Instead, the inhibitory effect of SP600125 on mitotic entry predominantly occurs upstream of Aurora A kinase and Polo-like kinase 1, resulting in a failure to remove the inhibitory phosphorylation of Cdk1. Importantly, our results directly show that the inhibition of Cdk1 activity and the persistence of Cdk2 activity in G2 cells induces endoreplication without mitosis. Furthermore, endoreplication from G2 phase is independent of p53 control.

Laser wakefield accelerators offer electron beams which could be useful for many applications. However, the problem of stabilizing the electron beam parameters has not been resolved yet. Here, we propose a method to minimize the electron beam pointing and report the generation of a relativistic electron beam with a stabilized pointing angle of 2 mrad (rms). This was achieved by using asymmetric non-relativistic laser pulses interacting with low-density helium gas jet. In such a weakly-nonlinear regime, symmetric laser pulses were neither able to generate reproducible nor stable electron beams. Thus, we propose asymmetric laser pulses for generating electron beams having stable and small pointing angles from laser-plasma accelerators.

A pair of conventional permanent magnet quadrupoles is used to focus a 2.4 MeV laser-driven proton beam at a 1 Hz repetition rate. The magnetic field strengths are 55 and 60 T/m for the first and second quadrupoles, respectively. The proton beam is focused to a spot with a size of less than similar to 3x8 mm(2) at a distance of 650 mm from the source. This result is in good agreement with the Monte Carlo particle trajectory simulation.

Magnetic domain walls in patterned permalloy ring elements of different widths and thicknesses have been probed by magnetic force microscopy and micromagnetic simulations. We report the experimental observation of antivortex structures in single-layer magnetic rings, previously only theoretically predicted. Furthermore, vortex-antivortex chains are observed on occasion in wider rings that prefer a circulating flux closure state. It is possible that they are pinned transient states of the relaxation path from the magnetically saturated to the circulating flux closure state. Similar tendencies are seen in micromagnetic simulations implying that vortex-antivortex pair nucleation and annihilation are fundamental parts of the said relaxation. Finally we present a phase diagram of different domain-wall configurations as a function of ring width and thickness.

The authors describe firstly the lasers for high intensity physics experiments at JAEA including J-KAREN and JLITE-X lasers which can deliver 00TW and 0TW laser power, respectively. Secondly the authors describe demonstration of flying mirror technique which will become a new technique to make a coherent tunable x-ray source. Thirdly a femto-second laser driven incoherent soft x-ray source and its imaging applications for nano-structures are described. The th topic includes femto-second laser driven multiple quantum beam generation and its applications using a laser driven thin foil target.

As a benchmark experiment to realize a novel and compact laser driven proton accelerator whose significant features are high number density in a short pulse width (similar to ns), 2.4 MeV laser driven proton beam is stably focused at I Hz repetition rate by using a pair of permanent quadrupole magnets (PMQs) with large apertures whose diameters and field strengths are 3.5 cm and 55T/m for the first and 2.3 cm and 60T/m for the second magnets, respectively. The proton beam has been focused to a focal spot of 3x8mm(2) in horizontal and vertical direction (full width at half maximum) at 650 similar to mm from the source, which is well reproduced by the simulation. The further optimization of the focusing system will sure to pave a way to the novel proton accelerator with which we can investigate the physics appeared in the short time scale as well as that in a high energy density matter, oncology, astrophysics, and so on.

BackgroundIn this retrospective study, we developed and internally validate a nomogram for predicting 5-year metastasis probability for nonmetastatic extremity osteosarcoma.Patients and methodsWe reviewed 365 osteosarcoma patients treated at our institute from 1990 to 2003. Clinicopathologic variables were recorded. Multivariate analysis using Cox proportional hazards regression was done and this Cox model was used as the basis for the nomogram.ResultsBy American Joint Committee on Cancer (AJCC) staging system, 141 patients (38.6%) were stage IIA and 224 (61.4%) were stage IIB. Multivariate Cox model identified patient age at diagnosis, tumor size, humeral location, and tumor necrosis rate after chemotherapy as correlated with metastasis-free survival. The degree of contribution of each covariate to the total point was tumor location, tumor necrosis rate, maximal tumor diameter, and age in decreasing order. The concordance index for the model was 0.78. Nomogram discrimination was superior to that of AJCC stage (concordance index 0.78 versus 0.68; P = 0.02) and histologic response grouping (concordance index 0.78 versus 0.69; P = 0.0004).ConclusionsWe devised a nomogram for nonmetastatic osteosarcoma that proposes improved estimates of metastasis over AJCC staging system or tumor necrosis rate. We suggest that this nomogram allows individualized risk assessments and could be used as the basis for risk-adapted therapy.

We describe results of experiments on laser-driven proton acceleration and corresponding laser-plasma diagnostics performed with the multi-10-TW J-KAREN laser. The laser consists of a high-pulse-energy oscillator, saturable absorber, stretcher, Optical Parametric Chirped Pulse Amplifier (OPCPA), two 4-pass Ti:Sapphire amplifiers, and compressor. The final amplifier is cryogenically cooled down to 100 K to avoid thermal lensing. The laser provides similar to 30 fs, similar to 1 J, high-contrast pulses with the nanosecond contrast better than 10(10). The peak intensity is 10(20) W/cm(2) with the 3-4 mu m focal spot. Using few-mu m tape and sub-mu m ribbon targets we produced protons with the energies up to 4 MeV. The tape target and repetitive laser operation allowed achieving proton acceleration at 1 Hz. We found significant differences in stability and angular distribution of proton beam in high-contrast and normal-contrast modes. The plasma diagnostics included interferometry and measurement of the target reflectivity. The latter provides convenient diagnostics of the laser contrast in the ion acceleration, harmonics generation, and other laser - solid target interaction experiments.

Spatial characteristics of Ni-like silver x-ray laser using grazing incidence pumping (GRIP) schemes were investigated. We succeeded in lasing from a nickellike silver plasma in the GRIP geometry using both a double pump laser pulse as well as a single-profiled pulse.The transverse profile of the intensity distribution as well as the spatial coherence of both variants of Ni-like Ag x-ray laser were determined by far-field measurements and the Young's double slit interferometry. The x-ray laser pumped by a single-profiled pulse showed the output beam with a highly coherent part of a reasonable volume containing about 3% of the total photon number

An ion spectrometer, composed of a time-of-flight spectrometer (TOFS) and a Thomson parabola spectrometer (TPS), has been developed to measure energy spectra and to analyze species of laser-driven ions. Two spectrometers can be operated simultaneously, thereby facilitate to compare the independently measured data and to combine advantages of each spectrometer. Real-time and shot-to-shot characterizations have been possible with the TOFS, and species of ions can be analyzed with the TPS. The two spectrometers show very good agreement of maximum proton energy even for a single laser shot. The composite ion spectrometer can provide two complementary spectra measured by TOFS with a large solid angle and TPS with a small one for the same ion source, which are useful to estimate precise total ion number and to investigate fine structure of energy spectrum at high energy depending on the detection position and solid angle. Advantage and comparison to other online measurement system, such as the TPS equipped with microchannel plate, are discussed in terms of overlay of ion species, high-repetition rate operation, detection solid angle, and detector characteristics of imaging plate.