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.

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.

Retraction: Pressure-Induced Superconducting State of Europium Metal at Low Temperatures [Phys. Rev. Lett. 102, 197002 (2009)].

Retraction of DOI: 10.1103/PhysRevLett.102.197002.

Dependence of the V/III Ratio on Indium Incorporation in InGaN Films Grown by Metalorganic Vapour Phase Epitaxy.

InGaN epitaxial layers were grown on c-plane sapphire substrates using the metalorganic vapour phase epitaxy (MOVPE) system at 760 °C. By varying the total flow rate of group-III sources (TMI+TEG) with a fixed molar ratio of group-III sources [TMI/(TMI+TEG)], the influence of V/III ratio were investigated from 4500 to 20000. The grown N-polar InGaN layers were investigated by atomic force microscopy and it is found that the surface roughness decreases with increasing the V/III ratios. High resolution X-ray diffraction analyses show that the phase separation decreases with increasing the V/III ratios. Photoluminescence measurements reveal that the peak position of the band-edge emission shifted toward the shorter wavelength with increasing the V/III ratios. Reciprocal space mapping (RSM) analyses were carried out on InGaN films. At low V/III ratio, the phase separation can be detected in InGaN films.

Characterization of high spatial resolution lithium fluoride X-ray detectors.

The response of lithium fluoride (LiF) crystal detectors to monochromatic X-rays is measured in the multi-kilo-electron-volt range. This response, as a function of the X-ray dose, is independent of photon energy with no saturation level found. The response, as a function of the incident energy flux, is found to increase for photons of lower energy due to the differing attenuation lengths of X-ray photons within the crystal. Small differences are seen between different confocal microscopes used to scan the data, suggesting the need for absolute calibration. The spatial resolution of the LiF is also measured (1.19-1.36 µm) and is found to be independent of incident photon energy. Finally, a photometric study is performed in order to assess the feasibility of using these detectors at current X-ray free electron laser and laser facilities worldwide.

Erratum: Structural and Valence Changes of Europium Hydride Induced by Application of High-Pressure H_{2} [Phys. Rev. Lett. 107, 025501 (2011)].

This corrects the article DOI: 10.1103/PhysRevLett.107.025501.

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.

Prevalence of, and risk factors for, carriage of carbapenem-resistant Enterobacteriaceae among hospitalized patients in Japan.

BACKGROUND: The prevalence of carbapenem-resistant Enterobacteriaceae (CRE) has been reported to be lower in Japan than in many other countries. However, extensive surveillance for CRE carriage has not been performed in Japan. AIM: To investigate the prevalence of CRE carriage in Japan among convalescent patients considered to be at high risk of being CRE carriers using an improved selective culture medium. METHODS: A cross-sectional survey was conducted in 22 acute care hospitals (ACHs) and 21 long-term care hospitals (LTCHs) in northern Osaka from December 2015 to January 2016. Patients who used incontinence aids, an enteral feeding tube or a urinary catheter were enrolled. Faecal specimens were examined using the newly developed M-ECC for imipenemase (IMP)-producing CRE, which is the most prevalent form of CRE in Japan. The positive isolates were analysed by polymerase chain reaction and sequencing. Risk factors associated with carriage were analysed by logistic regression. FINDINGS: Among 1507 patients, 184 (12.2%) carried CRE. The percentage of positive patients was significantly higher in LTCHs (14.9%) than in ACHs (3.6%) (P<0.001). Risk factors for CRE carriage were longer hospital stay [odds ratio (OR) 2.59; 95% confidence interval (CI) 1.87-3.60], enteral feeding (OR 3.03, 95% CI 2.08-4.42) and antibiotic exposure (OR 2.00, 95% CI 1.40-2.87). Among the 233 CRE isolates identified, 223 were IMP producers; the remaining isolates did not produce carbapenemase. CONCLUSIONS: This is the first Japanese report to demonstrate the significant spread of CRE in both ACHs and LTCHs using an improved selective medium. A coordinated regional approach may help to prevent further spread.

Retroperitoneal leiomyosarcoma: a case report.

Retroperitoneal leiomyosarcoma is a relatively rare and aggressive tumor. Because of its rarity, it is difficult to arrive at a definite diagnosis preoperatively and to design an effective strategy. Here the authors report a case of peritoneal leiomyosarcoma in which diagnosis was difficult because the clinical course resembled that of ovarian cancer. A 77-year-old woman diagnosed with ovarian cancer underwent laparotomy. The excised tumor contained a necrotic polypoid mass that histologically displayed the features of leiomyosarcoma. The patient received adjuvant chemotherapy with a combination of gemcitabine and docetaxel but died two months after surgery owing to the aggressive behavior of the tumor. Because the preoperative diagnosis in this case was ovarian cancer, arriving at a treatment strategy assuming peritoneal leiomyosarcoma was difficult. If complete surgical resection of tumor is not performed, as in the present case, the prognosis can be extremely poor.

Evaluation of antimicrobial stewardship (AS) for appropriate use of antimicrobial agents.

We implemented an antimicrobial stewardship (AS) program whereby pharmacists sought appropriate use of antimicrobial agents in January 2012. At that time, we targeted anti-methicillin-resistant Staphylococcus aureus (MRSA) agents and carbapenems; however, in January 2014, we added tazobactam/piperacillin (TAZ/PIPC). We evaluated outcomes using multilateral analyses. The average one-day dosage of carbapenems increased; however, the duration of administration and number of recipient patients decreased significantly (P < 0.01). Moreover, the percentage of patients receiving meropenem (MEPM), for whom the time above minimal inhibitory concentration (MIC) was 40% or higher increased (P < 0.01). In contrast, patient utilization of TAZ/PIPC increased significantly after targeting of carbapenems as specific antibacterial agents. However, after TAZ/PIPC was targeted as a specific antibacterial agent, the number of TAZ/PIPC administrations decreased significantly (P < 0.01). The duration of hospitalization and mortality rate in patients receiving specific antibacterial agents significantly decreased after implementation of the AS program (P < 0.01). In conclusion, pharmacist's interventions to provide AS and patient follow-up reduced improper use and promoted proper administration of antibacterial agents. Furthermore, AS was effective in improving patient prognoses and suppressing drug-resistant strains, as well as promoting effective treatment.

Coherent X-ray beam metrology using 2D high-resolution Fresnel-diffraction analysis.

Direct metrology of coherent short-wavelength beamlines is important for obtaining operational beam characteristics at the experimental site. However, since beam-time limitation imposes fast metrology procedures, a multi-parametric metrology from as low as a single shot is desirable. Here a two-dimensional (2D) procedure based on high-resolution Fresnel diffraction analysis is discussed and applied, which allowed an efficient and detailed beamline characterization at the SACLA XFEL. So far, the potential of Fresnel diffraction for beamline metrology has not been fully exploited because its high-frequency fringes could be only partly resolved with ordinary pixel-limited detectors. Using the high-spatial-frequency imaging capability of an irradiated LiF crystal, 2D information of the coherence degree, beam divergence and beam quality factor M2 were retrieved from simple diffraction patterns. The developed beam metrology was validated with a laboratory reference laser, and then successfully applied at a beamline facility, in agreement with the source specifications.

Systematic review and meta-analysis of hepatitis C virus infection in the Democratic Republic of Congo.

OBJECTIVES: Hepatitis C virus (HCV) infection is endemic in the Democratic Republic of the Congo (DRC), where the prevalence of HCV antibodies (anti-HCV) is reported to range from 0.2% to 13.7%. However, the reported prevalence rates have been inconsistent. Therefore, a meta-analysis of observational studies was conducted to provide updates on the prevalence of HCV infection in the DRC. STUDY DESIGN: Systematic review and meta-analysis. METHODS: Medline, EMBASE and Google Scholar were searched for publications reporting on HCV infection in the DRC up to autumn 2015. In addition, a manual search was undertaken to detect relevant papers. Studies performed in groups at low risk of HCV (blood donors and pregnant women) were used for the meta-analysis. The random effects model was used to estimate the pooled prevalence of anti-HCV. RESULTS: Sixteen studies with 13,799 participants (aged 6 months-71 years) met the inclusion criteria. The studies were performed in blood donors, pregnant women, military personnel, individuals with human immunodeficiency virus, children, commercial sex workers, Congolese patients living in Canada, patients with sickle cell disease and hospitalized patients. The reviewed studies revealed the presence of anti-HCV in almost all studied age groups and did not differ between sexes. The pooled prevalence of anti-HCV was 2.9% [95% confidence interval 1.5-4.3%]. Subgroup analyses revealed that the prevalence rates of anti-HCV in blood donors and pregnant women were 2.7% (95% confidence interval: 1.1-4.4%) and 3.3% (1.4-5.1%), respectively. CONCLUSIONS: HCV infection remains an issue of public concern in the DRC, demonstrating a need for adequate hepatitis control programmes. Efforts must be made to virtually eliminate transfusion-transmitted HCV throughout the country.

Risk factors for neutropenia with lenalidomide plus dexamethasone therapy for multiple myeloma.

Neutropenia may develop as an adverse event in patients with multiple myeloma receiving lenalidomide (LEN) plus dexamethasone (DEX) therapy. In the present study, we examined the risk factors associated with grade 3/4 neutropenia during the first cycle of LEN plus DEX therapy. We observed that hemoglobin level (≤ 8.5 g/dl) was a significant risk factor for grade 3/4 neutropenia during the first cycle of therapy (odds ratio: 19.40; 95% confidence interval: 2.68-141.00; p < 0.01). thus, our findings suggest that determining the hemoglobin level could be useful in the risk management for neutropenia in patients receiving LEN plus DEX therapy.

Antibacterial therapy of aspiration pneumonia in patients with methicillin-resistant Staphylococcus aureus-positive sputum: identification of risk factors.

Inappropriate antimicrobial treatment could adversely affect the recovery of patients with aspiration pneumonia. We attempted to identify inappropriate antibacterial treatment and to determine the standard use of anti-methicillin-resistant Staphylococcus aureus (MRSA) drugs in aspiration pneumonia patients with MRSA-positive in sputum. Aspiration pneumonia patients with MRSA-positive sputum treated between January 2013 and May 2013 were included in this study to determine the risk factors for death during hospitalization. The relationship between anti-MRSA medicine use and death during hospitalization was also investigated. More than 107 MRSA colony-forming units in sputum culture, creatinine clearance of less than 30 mL/min, and quinolone use were found to be risk factors for death during hospitalization. The death rate during hospitalization was significantly lower in cases a Geckler classification of 4 or 5 when anti-MRSA treatment was initiated soon after the culture was obtained. Therefore, we concluded that the use of quinolones as antibacterial treatment in aspiration pneumonia patients with MRSA-positive sputum should be avoided and that anti-MRSA treatment should be started in cases with good quality sputum cultures.

A comparative analysis of micafungin and caspofungin for empirical antifungal therapy in antibiotic-unresponsive febrile patients with hematologic malignancies.

This study was retrospectively carried out to compare the efficacy of echinocandins such as micafungin (MCFG) and caspofungin (CPFG) in the treatment of antibiotic-unresponsive febrile patients with hematologic malignancies. A total of 163 patients received either MCFG or CPFG. We evaluated the efficacy of echinocandin against fever decline in all patients. Fever decline, defined as a body temperature of less than 37.5 °C sustained for more than 48 h without scheduled antipyretic medication. Efficacy assessments showed that the incidence of fever decline was not significantly different between the MCFG and CPFG groups (P=0.599). The median number of days from the start of echinocandin administration to fever decline was 5 in both the MCFG and CPFG groups. Multivariate analysis showed that the use of anti-MRSA drugs (HR, 0.64; 95%CI, 0.45-0.90; P=0.011) and a change from echinocandins to voriconazole or liposomal-amphotericin B (HR, 0.50; 95%CI, 0.30-0.74; P<0.001) are significant risk factors for sustained fever. A significant difference (P=0.002) in incidence of fever decline was however associated with differences in the timing of anti-MRSA drug administration. The median number of days from the start of echinocandin administration to fever decline was 5 when administration of the anti-MRSA drug occurred "simultaneously or prior to echinocandin start" and 11 in the "next day or later of echinocandin start" group. In other words, starting anti-MRSA drug treatment after echinocandin treatment is a risk factor. In conclusion, MCFG and CPFG have similar efficacy as empirical antifungal agents in the treatment of antibioticunresponsive febrile patients with hematopoietic malignancies.

Effect of sapphire nitridation and group-III source flow rate ratio on In-incorporation into InGaN grown by metalorganic vapor phase epitaxy.

In-composition of N-polar InGaN films on the sapphire substrate with the surface nitridation was investigated. By varying the ratio of the group-III source flow rate from 0.7 to 0.95, the In-composition and the surface morphologies of InGaN films were changed. The In-composition of N-polar InGaN films was affected by the strain relaxation and the surface morphologies.

Finite spot effects on radiation pressure acceleration from intense high-contrast laser interactions with thin targets.

Short pulse laser interactions at intensities of 2×10(21) W cm(-2) with ultrahigh contrast (10(-15)) on submicrometer silicon nitride foils were studied experimentally by using linear and circular polarizations at normal incidence. It was observed that, as the target decreases in thickness, electron heating by the laser begins to occur for circular polarization leading to target normal sheath acceleration of contaminant ions, while at thicker targets no acceleration or electron heating is observed. For linear polarization, all targets showed exponential energy spreads with similar electron temperatures. Particle-in-cell simulations demonstrate that the heating is due to the rapid deformation of the target that occurs early in the interaction. These experiments demonstrate that finite spot size effects can severely restrict the regime suitable for radiation pressure acceleration.

PI3K/Akt signalling is required for the attachment and spreading, and growth in vivo of metastatic scirrhous gastric carcinoma.

BACKGROUND: PI3K/Akt (PKB) pathway has been shown in several cell types to be activated by ligands to cell surface integrins, leading to the metastasis of tumour cells. The signalling pathways involved in the metastatic spread of human scirrhous gastric carcinoma cells have not been defined. METHODS: The role of the PI3K/Akt pathway in an extensive peritoneal-seeding cell line, OCUM-2MD3 and a parental cell line, OCUM-2M, was investigated by assessing in vitro adhesion and spreading assay, and in vivo peritoneal metastatic model. We also examined the correlation of PI3K/Akt pathway with integrin signals by immunoprecipitations, using cells by transfection with mutant p85 (Δp85). RESULTS: Adhesiveness and spreading of OCUM-2MD3 cells on collagen type IV was significantly decreased by PI3K inhibitors and expression of mutant p85, but not by inhibitors of protein kinase C (PKC) or extracellular signal-regulated kinase (ERK). Immunoprecipitation studies indicated that the PI3K/Akt pathway was associated with integrin signalling through Src and vinculin. In an in vivo experimental metastasis model, p85 inhibition reduced peritoneal metastasis of OCUM-2MD3 cells. CONCLUSION: PI3K/Akt signalling may be required for integrin-dependent attachment and spreading of scirrhous gastric carcinoma cells, and would be translated into generating better strategies to optimise their use in cancer clinical trials.

Large amplitude fluxional behaviour of elemental calcium under high pressure.

Experimental evidences are presented showing unusually large and highly anisotropic vibrations in the "simple cubic" (SC) unit cell adopted by calcium over a broad pressure ranging from 30-90 GPa and at temperature as low as 40 K. X-ray diffraction patterns show a preferential broadening of the (110) Bragg reflection indicating that the atomic displacements are not isotropic but restricted to the [110] plane. The unusual observation can be rationalized invoking a simple chemical perspective. As the result of pressure-induced s → d transition, Ca atoms situated in the octahedral environment of the simple cubic structure are subjected to Jahn-Teller distortions. First-principles molecular dynamics calculations confirm this suggestion and show that the distortion is of dynamical nature as the cubic unit cell undergoes large amplitude tetragonal fluctuations. The present results show that, even under extreme compression, the atomic configuration is highly fluxional as it constantly changes.