Erratum: Using Diffuse Scattering to Observe X-Ray-Driven Nonthermal Melting [Phys. Rev. Lett. 126, 015703 (2021)].

This corrects the article DOI: 10.1103/PhysRevLett.126.015703.

Micron-scale phenomena observed in a turbulent laser-produced plasma.

Turbulence is ubiquitous in the universe and in fluid dynamics. It influences a wide range of high energy density systems, from inertial confinement fusion to astrophysical-object evolution. Understanding this phenomenon is crucial, however, due to limitations in experimental and numerical methods in plasma systems, a complete description of the turbulent spectrum is still lacking. Here, we present the measurement of a turbulent spectrum down to micron scale in a laser-plasma experiment. We use an experimental platform, which couples a high power optical laser, an x-ray free-electron laser and a lithium fluoride crystal, to study the dynamics of a plasma flow with micrometric resolution (~1µm) over a large field of view (>1 mm2). After the evolution of a Rayleigh-Taylor unstable system, we obtain spectra, which are overall consistent with existing turbulent theory, but present unexpected features. This work paves the way towards a better understanding of numerous systems, as it allows the direct comparison of experimental results, theory and numerical simulations.

Liquid Structure of Tantalum under Internal Negative Pressure.

In situ femtosecond x-ray diffraction measurements and ab initio molecular dynamics simulations were performed to study the liquid structure of tantalum shock released from several hundred gigapascals (GPa) on the nanosecond timescale. The results show that the internal negative pressure applied to the liquid tantalum reached -5.6 (0.8) GPa, suggesting the existence of a liquid-gas mixing state due to cavitation. This is the first direct evidence to prove the classical nucleation theory which predicts that liquids with high surface tension can support GPa regime tensile stress.

Using Diffuse Scattering to Observe X-Ray-Driven Nonthermal Melting.

We present results from the SPring-8 Angstrom Compact free electron LAser facility, where we used a high intensity (∼10^{20} W/cm^{2}) x-ray pump x-ray probe scheme to observe changes in the ionic structure of silicon induced by x-ray heating of the electrons. By avoiding Laue spots in the scattering signal from a single crystalline sample, we observe a rapid rise in diffuse scattering and a transition to a disordered, liquidlike state with a structure significantly different from liquid silicon. The disordering occurs within 100 fs of irradiation, a timescale that agrees well with first principles simulations, and is faster than that predicted by purely inertial behavior, suggesting that both the phase change and disordered state reached are dominated by Coulomb forces. This method is capable of observing liquid scattering without masking signal from the ambient solid, allowing the liquid structure to be measured throughout and beyond the phase change.

Ion-production efficiency of a singly charged ion source developed toward a 11C irradiation facility for cancer therapy.

The ion-production efficiency of a newly developed singly charged ion source (SCIS) has been investigated to discuss the possibility of it being used in an isotope separation on-line system that provides 11C ions for heavy-ion cancer therapy with simultaneous verification of the irradiation field using positron emission tomography. The SCIS uses a low-energy hollow electron beam to produce singly charged carbon ions efficiently. To deliver sufficient 11C ions to the treatment room from a limited amount of 11C molecules, which are produced from a boron compound target and proton-beam irradiation via the 11B(p,n)11C reaction, the SCIS must have high ion-production efficiency. To realize this high efficiency, the SCIS was designed using a three-dimensional particle-in-cell code in previous work. With the fabricated SCIS, we performed experiments to measure the efficiency of producing CO2 + ions from nonradioactive 12CO2 molecules and C+ ions from nonradioactive 12CH4 molecules. We found that the SCIS achieved efficiencies of εC+ =4×10-3 (0.4%) for C+ production and εCO2 + =0.107 (10.7%) for CO2 + production.

Singly charged ion source designed using three-dimensional particle-in-cell method.

A singly charged ion source (SCIS) has been designed using a newly developed three-dimensional particle-in-cell (PIC) code. The SCIS is to be used in an isotope separation on-line (ISOL) system that provides 11C ions for heavy-ion cancer therapy with simultaneous verification of the dose distribution using positron emission tomography. The SCIS uses low-energy electron beams to produce singly charged carbon ions efficiently and maintain a high vacuum in the ISOL system. Because the SCIS has to realize a production efficiency of 1% if its carbon ions are to be used in the ISOL system, a suitable design for the SCIS was investigated by using the developed PIC code to study the beam trajectories of the electrons and extracted ions. The simulation results show that hollow electron beams are produced in the designed SCIS resulting in a high effective electron current. The results also predict that the designed SCIS would realize ion-production efficiencies (IPEs) of ε SCIS ≃ 6.7% for C O 2 + production from CO2 gas and ε SCIS ≃ 0.1% for C+ production from CH4 gas. Moreover, to examine the validity of the developed code and confirm that the SCIS was able to be designed appropriately, the space-charge-limited current of the electron gun and the total IPE obtained by adding the IPEs of each ion were compared between the experiment and the simulation.

Advanced high resolution x-ray diagnostic for HEDP experiments.

High resolution X-ray imaging is crucial for many high energy density physics (HEDP) experiments. Recently developed techniques to improve resolution have, however, come at the cost of a decreased field of view. In this paper, an innovative experimental detector for X-ray imaging in the context of HEDP experiments with high spatial resolution, as well as a large field of view, is presented. The platform is based on coupling an X-ray backligther source with a Lithium Fluoride detector, characterized by its large dynamic range. A spatial resolution of 2 µm over a field of view greater than 2 mm2 is reported. The platform was benchmarked with both an X-ray free electron laser (XFEL) and an X-ray source produced by a short pulse laser. First, using a non-coherent short pulse laser-produced backlighter, reduced penumbra blurring, as a result of the large size of the X-ray source, is shown. Secondly, we demonstrate phase contrast imaging with a fully coherent monochromatic XFEL beam. Modeling of the absorption and phase contrast transmission of X-ray radiation passing through various targets is presented.

A singly charged ion source for radioactive ¹¹C ion acceleration.

A new singly charged ion source using electron impact ionization has been developed to realize an isotope separation on-line system for simultaneous positron emission tomography imaging and heavy-ion cancer therapy using radioactive (11)C ion beams. Low-energy electron beams are used in the electron impact ion source to produce singly charged ions. Ionization efficiency was calculated in order to decide the geometric parameters of the ion source and to determine the required electron emission current for obtaining high ionization efficiency. Based on these considerations, the singly charged ion source was designed and fabricated. In testing, the fabricated ion source was found to have favorable performance as a singly charged ion source.

Development of a compact ECR ion source for various ion production.

There is a desire that a carbon-ion radiotherapy facility will produce various ion species for fundamental research. Although the present Kei2-type ion sources are dedicated for the carbon-ion production, a future ion source is expected that could provide: (1) carbon-ion production for medical use, (2) various ions with a charge-to-mass ratio of 1/3 for the existing Linac injector, and (3) low cost for modification. A prototype compact electron cyclotron resonance (ECR) ion source, named Kei3, based on the Kei series has been developed to correspond to the Kei2 type and to produce these various ions at the National Institute of Radiological Sciences (NIRS). The Kei3 has an outer diameter of 280 mm and a length of 1120 mm. The magnetic field is formed by the same permanent magnet as Kei2. The movable extraction electrode has been installed in order to optimize the beam extraction with various current densities. The gas-injection side of the vacuum chamber has enough space for an oven system. We measured dependence of microwave frequency, extraction voltage, and puller position. Charge state distributions of helium, carbon, nitrogen, oxygen, and neon were also measured.

Electron string ion sources for carbon ion cancer therapy accelerators.

The type of the Electron String Ion Sources (ESIS) is considered to be the appropriate one to produce pulsed C(4+) and C(6+) ion beams for cancer therapy accelerators. In fact, the new test ESIS Krion-6T already now provides more than 10(10) C(4+) ions per pulse and about 5 × 10(9) C(6+) ions per pulse. Such ion sources could be suitable to apply at synchrotrons. It has also been found that Krion-6T can provide more than 10(11) C(6+) ions per second at the 100 Hz repetition rate, and the repetition rate can be increased at the same or larger ion output per second. This makes ESIS applicable at cyclotrons as well. ESIS can be also a suitable type of ion source to produce the (11)C radioactive ion beams. A specialized cryogenic cell was experimentally tested at the Krion-2M ESIS for pulse injection of gaseous species into the electron string. It has been shown in experiments with stable methane that the total conversion efficiency of methane molecules to C(4+) ions reached 5%÷10%. For cancer therapy with simultaneous irradiation and precise dose control (positron emission tomography) by means of (11)C, transporting to the tumor with the primary accelerated (11)C(4+) beam, this efficiency is preliminarily considered to be large enough to produce the (11)C(4+) beam from radioactive methane and to inject this beam into synchrotrons.

Cryogenic molecular separation system for radioactive (11)C ion acceleration.

A (11)C molecular production/separation system (CMPS) has been developed as part of an isotope separation on line system for simultaneous positron emission tomography imaging and heavy-ion cancer therapy using radioactive (11)C ion beams. In the ISOL system, (11)CH4 molecules will be produced by proton irradiation and separated from residual air impurities and impurities produced during the irradiation. The CMPS includes two cryogenic traps to separate specific molecules selectively from impurities by using vapor pressure differences among the molecular species. To investigate the fundamental performance of the CMPS, we performed separation experiments with non-radioactive (12)CH4 gases, which can simulate the chemical characteristics of (11)CH4 gases. We investigated the separation of CH4 molecules from impurities, which will be present as residual gases and are expected to be difficult to separate because the vapor pressure of air molecules is close to that of CH4. We determined the collection/separation efficiencies of the CMPS for various amounts of air impurities and found desirable operating conditions for the CMPS to be used as a molecular separation device in our ISOL system.

Prevalencia de las maloclusiones en el Departamento de Ortodoncia de la División de Estudios de Postgrado e Investigación de la Facultad de Odontología de la Universidad Nacional Autónoma de México / Prevalence of malocclusions at the Orthodontics Department of the Graduate School, National School of Dentistry, National University of Mexico (UNAM)

En la División de Estudios de Postgrado e Investigación de la Universidad Nacional Autónoma de México, en el Departamento de Ortodoncia, nosotros desarrollamos diferentes métodos analíticos y descriptivos, donde se realizó estudio estadístico de la clasificación esqueletal con una muestra de 428 pacientes que recibieron tratamiento de ortodoncia. Se seleccionaron personas entre 8 y 40 años de edad. Se capturaron datos de acuerdo a sexo, edad y maloclusión esqueletal para conocer el panorama epidemiológico. Después del análisis estadístico encontramos que el 53.3% de la muestra se encontraba, en clase I esqueletal, que el 64.7% era del sexo femenino y que el 52.08% se encontraba en el rango de edad de 13 a 19 años, además de otros datos.

At the Graduate and Research School of the National School of Dentistry, National University of Mexico (UNAM) we developed several analytic and descriptive methods. A statistical study of skeletal classification was undertaken with a sample of 428 patients subjected to orthodontic treatment. Age range of selected patients was 8-40 years. Data were collected according to gender, age and skeletal malocclusion in order to assess the epidemiological panorama. After statistical analysis, it was found among other data, that 53.3% of the sample was in skeletal class I, 64.7% were female and 52.08% was found to be in the 13 to 19 year age range.

Status of a compact electron cyclotron resonance ion source for National Institute of Radiological Sciences-930 cyclotron.

The Kei-source is a compact electron cyclotron resonance ion source using only permanent magnets and a frequency of 10 GHz. It was developed at the National Institute of Radiological Sciences (NIRS) for producing C(4+) ions oriented for high-energy carbon therapy. It has also been used as an ion source for the NIRS-930 cyclotron. Its microwave band region for the traveling-wave-tube amplifier and maximum output power are 8-10 GHz and 350 W, respectively. Since 2006, it has provided various ion beams such as proton, deuteron, carbon, oxygen, and neon with sufficient intensity (200 µA for proton and deuteron, 50 µA for C(4+), for example) and good stability for radioisotope production, tests of radiation damage, and basic research experiments. Its horizontal and vertical emittances were measured using a screen monitor and waist-scan. The present paper reports the current status of the Kei-source.

Status of ion sources at National Institute of Radiological Sciences.

The National Institute of Radiological Sciences (NIRS) maintains various ion accelerators in order to study the effects of radiation of the human body and medical uses of radiation. Two electrostatic tandem accelerators and three cyclotrons delivered by commercial companies have offered various life science tools; these include proton-induced x-ray emission analysis (PIXE), micro beam irradiation, neutron exposure, and radioisotope tracers and probes. A duoplasmatron, a multicusp ion source, a penning ion source (PIG), and an electron cyclotron resonance ion source (ECRIS) are in operation for these purposes. The Heavy-Ion Medical Accelerator in Chiba (HIMAC) is an accelerator complex for heavy-ion radiotherapy, fully developed by NIRS. HIMAC is utilized not only for daily treatment with the carbon beam but also for fundamental experiments. Several ECRISs and a PIG at HIMAC satisfy various research and clinical requirements.

Epidermotropic CD8+ cytotoxic T-cell lymphoma exhibiting a transition from the indolent to the aggressive phase, accompanied by emergence of CD7+ cells and formation of neutrophilic pustules.

A 47-year-old-man presented with rashes on his trunk and limbs, and a diagnosis of parapsoriasis was made. Ten years later, the rashes had progressed gradually to form plaques and tumours. Gene rearrangement studies revealed monoclonality of the T-cell receptor ß-chain (TCR-Jß)1 gene, and results of flow cytometry and immunohistochemical examination confirmed a diagnosis of epidermotropic CD8+ cytotoxic T-cell lymphoma. The clinical course of the disease remained indolent for some time, but about 2 years later, neutrophilic pustules formed on the surface of the skin lesions, and tumours developed in the patient's testes. Using flow cytometry, emergence of CD7+ cells was found. The patient died the following year of respiratory failure due to brain herniation. On postmortem examination, CD8+ tumour cells were found in the brain. This case demonstrates an unusually protracted indolent phase in a patient with cutaneous aggressive epidermotropic CD8+ cytotoxic T-cell lymphoma; its transition into the aggressive phase was accompanied by emergence of CD7+ cells and formation of neutrophilic pustules.

A novel nonsecosteroidal VDR agonist (CH5036249) exhibits efficacy in a spontaneous benign prostatic hyperplasia beagle model.

To date, there have been no reports showing the efficacy of nonsecosteroidal vitamin D receptor (VDR) agonists in a benign prostatic hyperplasia (BPH) animal model. To examine the efficacy of CH5036249, a novel nonsecosteroidal VDR agonist, we orally administered the compound at 0.03 microg/kg to a beagle model with spontaneous BPH. Prostate volume was checked by rectal ultrasonic probe periodically during 11 months of administration and the prostate tissues histologically examined. CH5036249 inhibited prostate growth in two out of three dogs compared with vehicle-treated dogs. In the prostate specimens, substantial atrophy of the epithelium was observed in all dogs administered CH5036249. At the dose given, serum calcium levels slightly increased in the CH5036249-treated dogs but stayed within a normal range. We next examined the cell growth inhibition of CH5036249 using human prostate stromal cells and found the cell growth inhibitory activity of CH5036249 to be comparable to that of 1alpha,25(OH)2D3. The bioavailability from oral administration in rats was 95.1% with a t1/2 of 17.6 h. Both micro-AMES and micronucleus tests were negative. Although the results are still preliminary, we consider the novel nonsecosteroidal VDR agonist CH5036249 to be a possible new drug candidate for the treatment of BPH in humans.

Deregulated expression of a novel component of TFTC/STAGA histone acetyltransferase complexes, rat SGF29, in hepatocellular carcinoma: possible implication for the oncogenic potential of c-Myc.

c-Myc N-terminal conserved domains, MbI and MbII, are essential for c-Myc-mediated transformation and transactivation. These domains recruit the STAGA (SPT3-TAF9-GCN5-acetyltransferase) coactivator complex, but not TFTC (TATA-binding protein-free TAF-containing) to the target gene promoter. Although components of this complex are well conserved between yeast and mammals, four mammalian orthologs of yeast SPT8, SPT20, SGF11 and SGF29 remain to be identified. Here, we isolated a rat ortholog of yeast SGF29, a component of yeast SAGA (SPT-ADA-GCN5-acetyltransferase) complex. Both rat (r) SGF29 and c-myc mRNAs were overexpressed in five out of the eight tested rodent tumor cells. rSGF29 directly interacted with rADA3 and co-immunoprecipitated with two other TFTC/STAGA components, rGCN5 and rSPT3. rSGF29 was recruited to the c-Myc target gene promoters together with c-Myc, and it activated c-Myc target gene expressions. Downregulation of rSGF29 suppressed the expression of c-Myc target genes and inhibited anchorage-independent growth and tumorigenicity and lung metastasis of rat hepatoma K2 cells when injected into nude mice. These results show that rSGF29 is a novel component of TFTC/STAGA complexes and could be involved in the c-Myc-mediated malignant transformation.