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The nonlinear interaction between electromagnetic waves and plasmas attracts significant attention in astrophysics because it can affect the propagation of Fast Radio Bursts (FRBs) -- luminous millisecond-duration pulses detected at radio frequency. The filamentation instability (FI) -- a type of nonlinear wave-plasma interaction -- is considered to be dominant near FRB sources, and its nonlinear development may also affect the inferred dispersion measure of FRBs. In this paper, we carry out fully kinetic particle-in-cell simulations of the FI in unmagnetized pair plasmas. Our simulations show that the FI generates transverse density filaments, and that the electromagnetic wave propagates in near vacuum between them, as in a waveguide. The density filaments keep merging until force balance between the wave ponderomotive force and the plasma pressure gradient is established. We estimate the merging timescale and discuss the implications of filament merging for FRB observations., Submitted to MNRAS

Monthly notices of the Royal Astronomical Society 501(4), 4837 - 4849 (2021). doi:10.1093/mnras/staa3901, Mildly relativistic shocks in magnetized electron���ion plasmas are investigated with 2D kinetic particle-in-cell simulations of unprecedentedly high resolution and large scale for conditions that may be found at internal shocks in blazar cores. Ion-scale effects cause corrugations along the shock surface whose properties somewhat depend on the configuration of the mean perpendicular magnetic field, that is either in or out of the simulation plane. We show that the synchrotron maser instability persists to operate in mildly relativistic shocks in agreement with theoretical predictions and produces coherent emission of upstream-propagating electromagnetic waves. Shock front ripples are excited in both mean-field configurations and they engender effective wave amplification. The interaction of these waves with upstream plasma generates electrostatic wakefields., Published by Oxford Univ. Press, Oxford

Particle acceleration at magnetized purely perpendicular relativistic shocks in electron-ion plasmas are studied by means of two-dimensional particle-in-cell simulations. Magnetized shocks with the upstream bulk Lorentz factor $\gamma_1 \gg 1$ are known to emit intense electromagnetic waves from the shock front, which induce electrostatic plasma waves (wakefield) and transverse filamentary structures in the upstream region via the stimulated/induced Raman scattering and the filamentation instability, respectively. The wakefield and filaments inject a fraction of incoming particles into a particle acceleration process, in which particles are once decoupled from the upstream bulk flow by the wakefield, and are piked up again by the flow. The picked-up particles are accelerated by the motional electric field. The maximum attainable Lorentz factor is estimated as $\gamma_{max,e} \sim \alpha\gamma_1^3$ for electrons and $\gamma_{max,i} \sim (1+m_e\gamma_1/m_i)\gamma_1^2$ for ions, where $\alpha \sim 10$ is determined from our simulation results. $\alpha$ can increase up to $\gamma_1$ for weakly magnetized shock if $\gamma_1$ is sufficiently large. This result indicates that highly relativistic astrophysical shocks such as external shocks of gamma-ray bursts can be an efficient particle accelerator., Comment: 14 pages, 13 figures, accepted to ApJ

Monthly notices of the Royal Astronomical Society 502(4), 5065-5074 (2021). doi:10.1093/mnras/stab220, Particle acceleration and heating at mildly relativistic magnetized shocks in electron-ion plasma are investigated with unprecedentedly high-resolution two-dimensional particle-in-cell simulations that include ion-scale shock rippling. Electrons are super-adiabatically heated at the shock, and most of the energy transfer from protons to electrons takes place at or downstream of the shock. We are the first to demonstrate that shock rippling is crucial for the energization of electrons at the shock. They remain well below equipartition with the protons. The downstream electron spectra are approximately thermal with a limited supra-thermal power-law component. Our results are discussed in the context of wakefield acceleration and the modelling of electromagnetic radiation from blazar cores., Published by Oxford Univ. Press, Oxford

We investigated electromagnetic precursor wave emission in relativistic shocks by using two-dimensional particle-in-cell simulations. We found that the wave amplitude is significantly enhanced by a positive feedback process associated with ion-electron coupling through the wakefields for high magnetization. The wakefields collapse during the nonlinear process of the parametric decay instability in the near-upstream region, where nonthermal electrons and ions are generated. The intense coherent emission and the particle acceleration may opperate in high-energy astrophysical objects., Comment: 7 pages, 4 figures, accepted to ApJL

We discuss a mechanism for intense electromagnetic wave emission at an astrophysical relativistic shock in a magnetized collisionless plasma. At the magnetized shock, the particle reflection by a compressed magnetic field of the shock produces a ring-like distribution in momentum, which gives rise to plasma instabilities. Intense and coherent high-frequency electromagnetic waves will be emitted if the synchrotron maser instability (SMI) is excited, whereas non-propagating magnetic fluctuations will be generated when the Weibel instability (WI) is the dominant mode. The problem is of great astrophysical interest because if intense radiation is emitted, the interaction with the upstream medium induces a large-amplitude electrostatic field (or Wakefield), which may play a role for the acceleration of ultra-high-energy cosmic rays. We review our recent effort to measure the efficiency of the electromagnetic wave emission using fully self-consistent, two-dimensional (2D) particle-in-cell (PIC) simulations for pair plasmas. We found that the emission efficiency in 2D was systematically lower than one dimensional (1D) PIC simulation results. However, the power remains finite even when the WI is active to generate large-amplitude magnetic fluctuations. Astrophysical implications of the present results are briefly discussed.

We investigated the precursor wave emission efficiency in magnetized purely perpendicular relativistic shocks in pair plasmas. We extended our previous study to include the dependence of upstream magnetic field orientations. We performed two-dimensional particle-in-cell simulations and focused on two magnetic field orientations: the magnetic field to be in the simulation plane (i.e., in-plane configuration) and perpendicular to the simulation plane (i.e., out-of-plane configuration). Our simulations in the in-plane configuration demonstrated that not only extraordinary but also ordinary mode waves are excited. We quantified the emission efficiency as a function of the magnetization parameter $\sigma_e$ and found that the large-amplitude precursor waves are emitted for a wide range of $\sigma_e$. We found that especially at low $\sigma_e$, the magnetic field generated by Weibel instability amplifies the ordinary mode wave power. The amplitude is large enough to perturb the upstream plasma, and transverse density filaments are generated as in the case of the out-of-plane configuration investigated in the previous study. We confirmed that our previous conclusion holds regardless of upstream magnetic field orientations with respect to the two-dimensional simulation plane. We discuss the precursor wave emission in three dimensions and the feasibility of wakefield acceleration in relativistic shocks based on our results., Comment: 17 pages, 14 figures, accepted to ApJ

We investigated the efficiency of coherent upstream large-amplitude electromagnetic wave emission via synchrotron maser instability at relativistic magnetized shocks by using two-dimensional particle-in-cell simulations. We considered the purely perpendicular shock in an electron-positron plasma. The coherent wave emission efficiency was measured as a function of the magnetization parameter {\sigma}, which is defined by the ratio of the Poynting flux to the kinetic energy flux. The wave amplitude was systematically smaller than that observed in one-dimensional simulations. However, it continued to persist, even at a considerably low magnetization rate, where the Weibel instability dominated the shock transition. The emitted electromagnetic waves were sufficiently strong to disturb the upstream medium, and transverse filamentary density structures of substantial amplitude were produced. Based on this result, we discuss the possibility of the wakefield acceleration model for the production of non-thermal electrons in a relativistic magnetized ion-electron shock., Comment: 19 pages, 16 figures, Revised Figure 15, results unchanged

The nested polymerase chain reaction (PCR) was clinically investigated to detect the mip gene of Legionella species. PCR detected 20 clinically important Legionella species , such as L. pneumophila, L. micdadei , and L. bozemanii . Eight species of Gram-positive and -negative bacteria other than Legionella species were negative for PCR. The sensitivity of PCR determined by the detection limit of DNA quantity was 1.0 pg for the first PCR, but the sensitivity increased approximately 100-fold to 10 fg following the second PCR. The nested PCR was applied to detect L. pneumophila in the sputum and pleural effusion fluid obtained from a patient with Legionnaires' disease. Both fluids were PCR positive, but culture was negative for L. pneumophila . Our results indicated that the nested PCR may be a useful tool for the rapid detection of L. pneumophila and the clinical diagnosis of Legionnaires' disease.

Anaerobic cultures were performed on various kinds of specimens obtained from 67 patients with respiratory infections. The infections consisted of 33 cases of pneumonia, 14 cases of lung abscess, 6 cases of pyothorax, 9 cases of chronic lower respiratory tract infection, and 5 cases of infection of pulmonary cyst. Specimens included bronchoscopic specimens obtained using a single tube or protected catheter brush (PCB), transtracheal aspirate, percutaneous lung aspirate, aspirate using a suction tube through the tracheostomy or intubation tube, and pleural fluid. Anaerobes were isolated in 80% of pyothorax, 43% of lung abscess, and 15% of pneumonia (42% of aspiration pneumonia), respectively. Anaerobes isolated frequently in respiratory infections included Prevotella spp., Fusobacterium spp., and Peptostreptococcus spp. In regard to the type of specimen, bronchial aspirate obtained by bronchoscopy was useful in examination of pneumonia, and was useful as percutaneous lung aspirate in examination of lung abscess. But there was discrepancy of culture results between specimens obtained by different methods in the same patient. To confirm anaerobes as pathogens in respiratory infections, it is necessary to select an appropriate method to obtain specimens and to interpret the culture results comprehensively.

The conventional method used for glass melting is air-fuel firing, which is inefficient, energy-intensive and time-consuming. In this study, an innovative in-flight melting technology was developed and applied to glass production for the purposes of energy conservation and environmental protection. Three types of heating sources, radio-frequency (RF) plasma, a 12-phase alternating current (ac) arc and an oxygen burner, were used to investigate the in-flight melting behavior of granulated powders. Results show that the melted particles are spherical with a smooth surface and compact structure. The diameter of the melted particles is about 50% of that of the original powders. The decomposition and vitrification degrees of the prepared powders decrease in the order of powders prepared by RF plasma, the 12-phase ac arc and the oxygen burner. The largest heat transfer is from RF plasma to particles, which results in the highest particle temperature (1810 °C) and the greatest vitrification degree of the raw material. The high decomposition and vitrification degrees, which are achieved in milliseconds, shorten the melting and fining times of the glass considerably. Our results indicate that the proposed in-flight melting technology is a promising method for use in the glass industry.

A 66-year-old male with chronic alcoholic liver injury was admitted on July 27, 1986 to our hospital with complaints of high fever, convulsion and skin erythema. He had consumed raw fish 3 days before, and had a scratch wound over the right arm and left leg because he had slipped in a small stream in the woods the day before admission. He was already in shock state with sepsis of V. vulnificus and DIC on admission. Although the treatment with ABPC, CP, CAZ, MINO for sepsis, and Heparin & Antithrombin III for DIC was immediately begun, he died only 10 hours after admission. On autopsy, the skin lesion revealed phlegmon with necrotizing angitis and the liver showed fatty changes with Mallory's body. The causative organism was detected from the blood and on autopsy from the skin wound, bile juice, liver, spleen, kidney and bone marrow, and its type was determined as a V. vulnificus serovar 4. It was suspected that the route of infection in this case was the raw fish rather than via the wound because the water in which he had been wounded was fresh water and the bacterium was not detected from the water, shells, nor moss existing there.

Liposomal amphotericin B was evaluated for toxicity, pharmacokinetic properties and therapeutic efficacy in invasive pulmonary aspergillosis in Sprague-Dawley rats. The protective effect of liposomes against the toxicity induced by repeated amphotericin B infusions was observed in a survival study of rats, thereby allowing higher dosages to be administered. Pharmacokinetic studies showed that liposomes led to high levels of amphotericin B in the spleen and liver. Drug levels in the lung were higher at ten minutes after intravenous injection of liposomal amphotericin B at 20 mg/kg than of free amphotericin B at 1.5 mg/kg. Efficacy was assessed in rats treated with cortisone acetate, fed a low-protein diet and infected transtracheally with 8 x 10(4) Aspergillus fumigatus spores to cause fetal pneumonia and pulmonary bleeding. Dosages of 20 or 4 mg/kg of liposomal amphotericin B, or 1.5 mg/kg of free amphotericin B were administered intravenously to rats once daily for 8 days. Control rats received saline. Twenty mg/kg of liposomal amphotericin B was as effective on survival rate as 1.5 mg/kg of free amphotericin B. However, 4 mg/kg of liposomal amphotericin B was less effective than 1.5 mg/kg of free amphotericin B, prolonging the mean survival time of rats treated with saline, which showed elevation of galactomannan antigen titers of Aspergillus fumigatus in sera and invasive proliferation or mycelia with bleeding in histopathological sections of the lung. We conclude that liposomal amphotericin B reduces toxicity of the drug, thereby increasing the concentration of the drug in the lung by high-dose administration, but decreases the efficacy of the drug in experimental pulmonary aspergillosis.

N-Terminal tetrapeptide analogs of fibrin alpha-chain were synthesized by the solution method using a new active ester, the ester of the oxime of p-nitroacetophenone, and by the solid-phase method. Their inhibitory effects on fibrinogen/thrombin clotting were examined. Of the synthetic peptides, amide analogs of Gly-Pro-Arg-Pro exhibited a more potent inhibitory effect.

In order to determine the optimal dose of cefepime (CFPM) for respiratory tract infections, a dose finding study was conducted in patients with chronic respiratory tract infections, and the clinical properties of the drugs were compared with those of ceftazidime (CAZ). Each drug was administered by intravenous drip infusion at the dose of 2 g/day of CFPM, 4 g/day of CFPM or 2 g/day of CAZ for 14 days. 1. The overall efficacy rates evaluated by the committee were 82.6% (19/23) for the CFPM 2 g/day group, 85.0% (17/20) for the 4 g/day group and 79.3% (23/29) for the CAZ 2 g/day group, with no statistically significant difference among the three groups. 2. The overall efficacy rates evaluated by the attending physicians were 91.3% (21/23) for the CFPM 2 g/day group, 78.9% (15/19) for the CFPM 4 g/day group and 75.9% (22/29) for the CAZ 2 g/day group, with no significant difference among the three groups. 3. Bacteriological eradication rates were 88.2% (15/17) for the CFPM 2 g/day group, 68.8% (11/16) for the CFPM 4 g/day group and 63.2% (12/19) for the CAZ 2 g/day group, with no statistically significant difference among the three groups. 4. The incidences of adverse reactions were 3.8% (1/26) for the CFPM 2 g/day group, 9.1% (2/22) for the CFPM 4 g/day group and 3.4% (1/29) for the CAZ 2 g/day group, with no significant difference among the three groups. The incidences of abnormal laboratory findings were 37.5% (9/24) for the CFPM 2 g/day group, 15.0% (3/20) for the CFPM 4 g/day group and 3.4% (1/29) for the CAZ 2 g/day group. There was a significant difference among the three groups. 5. Utility rates assessed by the committee were 81.8% (18/22) for the CFPM 2 g/day group, 76.2% (16/21) for the CFPM 4 g/day group and 75.9% (22/29) for the CAZ 2 g/day group. Utility rates assessed by attending physicians were 90.9% (20/22), 78.9% (15/19) and 72.4% (21/29), respectively. There was no significant difference among the three groups. From the above results, it is concluded that the optimal dosage of CFPM is 2 g/day for chronic respiratory tract infections.

We compared two latex agglutination tests for serum candidal antigen in murine models of systemic infection and gastrointestinal colonization. In the intravascular-infection model, mannan detection test was positive at 2 hours after inoculation, but Cand-Tec was less sensitive than mannan detection test in this model. In the gastrointestinal colonization model followed by systemic infection in neutropenic mice, the mannan antigen test became positive after 3 weeks of colonization with increased number of Candida of the stool, and Cand-Tec became positive after 5 weeks in neutropenic mice.

Clinical and bacteriological studies were carried out to investigate the isolation of MRSA from clinical materials, during the 4 years from 1985 to 1988 at the Hokusho Central Hospital. The isolation frequency of MRSA from Staphylococcus aureus increased from 5.6% (3 strains) in 1985 to 50.0% (90 strains) in 1988. MRSA from sputum and pressure sore increased significantly. However MRSA from outpatient and inpatient in the ward for common people were constant, about 20%. Inpatients in the ward for aged person were increased significantly from 13.6% (3 strains) to 67.0% (67 strains). Most of the patients with positive MRSA isolation had background diseases (88.3%) and were bedridden (78.4%). Patients with cerebrovascular disease were 55.9% of all of the cases. But most of the MRSA strains were resistant to CZX, FOM, DMPPC, CMX, CEZ, CZON, CZX, most of the MRSA strains were sensitive to RFP, VCM, MINO, IPM/CS.

An improved apparatus capable of quantatively measuring the inhomogeneity of glasses within several minutes was developed as a prototype for practical use. Inhomogeneities were measured for several kinds of glass articles on the market, such as plate, bottle and optical glasses etc. and a “relative homogeneity” has been proposed for the purpose of deciding a ranking of glasses measured in comparison to the powdered single crystal of CaF 2 as a standard material of uniformity.

Capsule-deficient Cryptococcus neoformans (CN-CD) infection is very rare. The authors recently experienced the case of CN-CD infection with the complication of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) in a 83 year old woman. She was admitted to our hospital with the complaints of fever and general fatigue on June 10, 1987. At the time of admission, there were no abnormal findings except a mildly lowered consciousness level on physical examination, there were no abnormal neurological finding nor meningeal signs. Laboratory data revealed a mild leukocytosis and hyponatremia. Chest X-P showed a few small nodular shadows scattered in both lungs. Antibiotics therapy was of no help and hyponatremia became worse. Then with the suspicion of SIADH, Demeclocycline was administered and limitation of water intake was decreased and hyponatremia improvement was used. Yeast-like fungi was detected in the venous blood culture and in the cerebrospinal fluid (cell count: 252/3) CN-CD by India-ink preparation and bacteriological nature were determined. We made a diagnosis of sepsis and meningitis by CN-CD accompanied with SIADH. In spite of Miconazole administration intravenously and intrathecally, she died 2 months after admission. The minimal inhibitory concentration (micrograms/ml) of antibiotics against the isolated CN-CD was as follows: Amphotericin B: 0.78, 5-PC: 1.56, Miconazole less than or equal to 0.05, Nystatin: 25, Ketoconazole: 0.78.