Observation of inverse Compton emission from a long γ-ray burst.

Long-duration γ-ray bursts (GRBs) originate from ultra-relativistic jets launched from the collapsing cores of dying massive stars. They are characterized by an initial phase of bright and highly variable radiation in the kiloelectronvolt-to-megaelectronvolt band, which is probably produced within the jet and lasts from milliseconds to minutes, known as the prompt emission1,2. Subsequently, the interaction of the jet with the surrounding medium generates shock waves that are responsible for the afterglow emission, which lasts from days to months and occurs over a broad energy range from the radio to the gigaelectronvolt bands1-6. The afterglow emission is generally well explained as synchrotron radiation emitted by electrons accelerated by the external shock7-9. Recently, intense long-lasting emission between 0.2 and 1 teraelectronvolts was observed from GRB 190114C10,11. Here we report multi-frequency observations of GRB 190114C, and study the evolution in time of the GRB emission across 17 orders of magnitude in energy, from 5 × 10-6 to 1012 electronvolts. We find that the broadband spectral energy distribution is double-peaked, with the teraelectronvolt emission constituting a distinct spectral component with power comparable to the synchrotron component. This component is associated with the afterglow and is satisfactorily explained by inverse Compton up-scattering of synchrotron photons by high-energy electrons. We find that the conditions required to account for the observed teraelectronvolt component are typical for GRBs, supporting the possibility that inverse Compton emission is commonly produced in GRBs.

Psychotropic agents. 3. 4-(4-Substituted piperidinyl)-1-(4-fluorophenyl)-1-butanones with potent neuroleptic activity.

A series of 1-(4-fluorophenyl)-4-(1-piperidinyl)-1-butanones substituted with benzimidazole, benzotriazole, or quinoxaline at the 4 position of the piperidine ring was synthesized and subjected to neuroleptic tests. Neuroleptic activities of several compounds were comparable to those of haloperidol. In particular, 4-[4-(2,3-dihydro-2-thioxo-1H-benzimidazol-1-yl)-1-piperidinyl]-1-(4-fluorophenyl)-1-butanone (10) was characterized by having a potent neuroleptic activity with less liability to the extrapyramidal side effect.

Bundle formation of smooth muscle desmin intermediate filaments by calponin and its binding site on the desmin molecule.

Smooth muscle basic calponin, a major actin-, tropomyosin-, and calmodulin-binding protein, has been examined for its ability to interact with desmin intermediate filaments from smooth muscle cells using sedimentation analysis, turbidity changes, chemical cross-linking, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI TOF/MS), and electron microscopic observations. Calponin interacted with desmin intermediate filaments in a concentration-dependent manner in vitro. The binding of calponin to desmin produced dense aggregates at 30 degrees C. The dense aggregates were observed by electron microscopy to be composed of large anisotropic bundles of desmin filaments, indicating that calponin forms bundles of desmin filaments. The addition of calmodulin or S100 to the mixture of calponin and desmin caused the removal of calponin from the desmin filaments and inhibited bundle formation in the presence of Ca(2+), but not in the presence of EGTA. Calponin-related proteins including G-actin, tropomyosin, and SM22, had little effect on the binding of calponin to desmin filaments, whereas tubulin weakly inhibited the binding. Desmin had little influence on the calponin-actin and calponin-tubulin interactions using the zero-length cross-linker, EDC. Domain mapping with chymotryptic digestion showed that the binding site of calponin resides within the central a-helical rod domain of the desmin molecule. The chemical cross-linked products of calponin and synthetic peptides (TQ27, TNEKVELQELNDRFANYIEKVRFLEQQ; EE24, EEELRELRRQVDALTGQRARVEVE) derived from the rod domain were detected by MALDI TOF/MS. Furthermore, the calponin-desmin interaction was significantly inhibited by the addition of EE24, but only slightly by TQ27. These results suggest that calponin may act as a cross-linking protein between desmin filaments as well as among intermediate filaments, microfilaments and microtubules in smooth muscle cells.

Semisynthetic beta-lactam antibiotics. II. Synthesis and antibacterial activity of 7beta-[2-(acylamino)-2- (2-aminothiazol-4-yl)acetamido]cephalosporins.

Cephalosporin derivatives (I) substituted with a neutral, acidic or basic amino acid group as the terminal group attached to the 2-amino-2-(2-aminothiazol-4-yl)acetamido side chain at the C-7 position were synthesized, and the effect of each group on antibacterial activity was examined. The derivatives bearing an amidino or guanidino group showed broad spectra of antibacterial activity similar to those of cefotaxime, but they were relatively sensitive to beta-lactamases.

Semisynthetic beta-lactam antibiotics. IV. Synthesis and antibacterial activity of 7 beta-[2-(hetero aromatic methoxyimino)-2-(2-aminothiazol-4-yl)acetamido]cephalosporins.

A series of 7 beta-[2-(hetero aromatic methoxyimino)-2-(2-aminothiazol-4-yl)acetamido]- cephalosporins have been synthesized and bacteriologically evaluated. Several substances in this series showed exceptional in vitro activity, especially those with a five-membered hetero aromatic substituent moiety at the 7-position and a quaternary ammonium group as the 3-function of the cephem nucleus. The most active derivative, 7 beta-[2-(imidazol-4-ylmethoxyimino)-2-(2-aminothiazol-4-yl)a cetamido]-3-(pyridiniomethyl)ceph-3-em-4-carboxylate (13a) was the most evenly balanced with respect to activity against Gram-positive and Gram-negative bacteria. Furthermore, 13 was stable to various types of beta-lactamases and had high affinities for penicillin binding protein-3 and -1Bs of both Escherichia coli and Pseudomonas aeruginosa.

Semisynthetic beta-lactam antibiotics. I. Synthesis and antibacterial activity of 7 beta-[2-aryl-2-(aminoacetamido)acetamido]-cephalosporins.

The synthesis and in vitro structure-activity relationships of cephalosporins having dipeptides substituted with various aryl groups as the side chain at the C-7 position have been outlined. Of these compounds, 2-aminothiazol derivatives showed a broad spectrum of enhanced antibacterial activity, and 7 beta-[DL-2-(D-aminopropionamido)-2-(2-aminothiazol-4-yl)acet amido]-3- [(1-methyl-1H-tetrazol-5-yl)thiomethyl]ceph-3-em-4-carboxyli c acid was the most balanced of these active derivatives with respect to both Gram-positive and Gram-negative strains.

Semisynthetic beta-lactam antibiotics. III. Synthesis and antibacterial activity of 7 beta-[2-(2-aminothiazol-4-yl)-2-(substituted carbamoylmethoxyimino)acetamido]cephalosporins.

Syntheses of cephalosporins modified with a 7 beta-[2-(2-aminothiazol-4-yl)-2-(substituted carbamoylmethoxyimino)acetamido] group at the C-7 position and with various hetero aromatics at the C-3 position are described. The effects of substituents on the carbamoyl group in the 7-side chain were investigated in order to improve antibacterial activity. Some of these compounds exhibited high antibacterial activity against Gram-positive and Gram-negative bacteria, including Pseudomonas aeruginosa, as well as good resistance to beta-lactamase.

High permissivity of the fish cell line SSN-1 for piscine nodaviruses.

Seventeen isolates of piscine nodavirus from larvae or juveniles of 13 marine fish species affected with viral nervous necrosis (VNN) were examined for their infectivity to a fish cell line SSN-1. Based on cytopathic effects (CPE) and virus antigen detection by fluorescent antibody technique (FAT) after incubation at 25 degrees C, the infectivity of these virus isolates was divided into 4 groups. Group 1, including 9 virus isolates from 4 species of grouper, 2 species of sea bass, barramundi, rock porgy, and Japanese flounder showed CPE characterized by rounded, granular cells with heavy cytoplasmic vacuoles within 3 d post-incubation (p.i.), and the monolayer partially or completely disintegrated over 3 to 6 d p.i. Scattered FAT-positive cells appeared at 3 h p.i. and spread through the cell sheet with an increasing fluorescence signal over 24 h p.i. Group 2, consisting of 3 virus isolates from striped jack, induced CPE with thin or rounded, granular, refractile cells without conspicuous vacuole formation, and extensive FAT-positive reaction was observed in a time course similar to that of Group 1. Cells inoculated with Group 3 (1 isolate from tiger puffer) developed no distinct CPE but viral infection was evidenced by localized FAT-positive cells. There were no FAT-positive cells in Group 4, which included 4 isolates from Japanese flounder, Pacific cod and Atlantic halibut. However, when incubation was performed at 20 degrees C, the SSN-1 cells inoculated with the Group 3 isolate showed CPE similar to that of Group 1 and extensive FAT-positive reaction. Evidence of virus proliferation at 20 degrees C was also obtained in Group 4 isolates. The virus titers in the infected fish varied from 10(11) to 10(16) tissue culture infectious dose (TCID50) g(-1) of fish. There is a good correlation between these infectivities to the SSN-1 cells and the coat protein gene genotypes of the isolates. The present results indicate that SSN-1 cells are useful for propagating and differentiating genotypic variants of piscine nodavirus.

Cloning of the fish cell line SSN-1 for piscine nodaviruses.

Six cell clones were derived from the SSN-1 cell line, which is composed of a mixed cell population and persistently infected with a C-type retrovirus (SnRV). These clones were susceptible to 4 piscine nodavirus strains belonging to different genotypes (SJNNV, RGNNV, TPNNV and *BFNNV [striped jack, redspotted grouper, tiger puffer and barfin flounder nervous necrosis viruses]). Three clones, designated A-6, E-9, and E-11, were highly permissive to nodavirus infection and production. The virus-induced cytopathic effects appeared as cytoplasmic vacuoles and intensive disintegration at 3 to 5 d post-incubation. These observations were highly reproducible and formed the basis for a successful virus titration system. Quantitative analysis using the cloned E-11 cell line clearly revealed differences in the optimal growth temperatures among the 4 genotypic variants: 25 to 30 degrees C for strain SGWak97 (RGNNV), 20 to 25 degrees C for strain SJNag93 (SJNNV), 20 degrees C for strain TPKag93 (TPNNV), and 15 to 20 degrees C for strain JFIwa98 (BFNNV). Electron microscopy demonstrated SnRV retrovirus particles only in A-6 and E-9 cells, but PCR amplification for the pol gene and LTR region of the proviral DNA indicated the presence of the retrovirus in the other clones, including E-11. The cell clones obtained in the present study will be more useful for qualitative and quantitative analyses of piscine nodaviruses than the SSN-1 cell line.

Experimental horizontal transmission of viral hemorrhagic septicemia virus (VHSV) in Japanese flounder Paralichthys olivaceus.

Infection by viral hemorrhagic septicemia virus (VHSV) has recently occurred among wild and farmed Japanese flounder Paralichthys olivaceus in Japan. In the present study, horizontal transmission of VHSV among Japanese flounder was experimentally demonstrated by immersion challenge. Exposure to a flounder isolate (Obama25) of VHSV revealed a dose-response, with higher mortality (81 and 70%) at the 2 higher exposure levels (6.0 and 4.0 log10 TCID50 ml(-1)). In a second experiment, high titers of VHSV were expressed from moribund and dead flounder based on virus detection in holding-tank waters 2 to 3 d prior to death of the fish and 1 d after death. The virus could not be detected in tank waters 2 d after death. Finally, a third cohabitation experiment in small tanks demonstrated horizontal transmission of VHSV from experimentally infected to uninfected fish.

Serological relationships among genotypic variants of betanodavirus.

Betanodaviruses, the causative agents of viral nervous necrosis or viral encephalopathy and retinopathy, are divided into 4 genotypes based on the coat protein gene (RNA2). In the present study, serological relationships among betanodavirus genotypic variants were examined by virus neutralization tests using rabbit antisera raised against purified virions of strains representative of each genotype. All 20 isolates examined shared epitopes for neutralizing, but they fell into 3 major serotypes (A, B, C). This sero-grouping is in part consistent with their genotypes, i.e. Serotype A for striped jack nervous necrosis virus (SJNNV) genotype, Serotype B for tiger puffer nervous necrosis virus (TPNNV) genotype, and Serotype C for both redspotted grouper nervous necrosis virus (RGNNV) and barfin flounder nervous necrosis virus (BFNNV) genotypes. The serological relatedness between RGNNV and BFNNV genotypes may result from their relatively higher similarity in RNA2 sequences. In neutralization tests using antisera of kelp grouper Epinephelus moara, which were raised against recombinant coat proteins representing each genotype, anti-SJNNV and anti-TPNNV sera neutralized only the homologous strain, and anti-RGNNV and anti-BFNNV sera reacted with both RGNNV and BFNNV strains. The present serological findings will be important in investigating the infectivity and host-specificity of betanodaviruses and in developing vaccines for the disease.

Fermi observations of high-energy gamma-ray emission from GRB 080916C.

Gamma-ray bursts (GRBs) are highly energetic explosions signaling the death of massive stars in distant galaxies. The Gamma-ray Burst Monitor and Large Area Telescope onboard the Fermi Observatory together record GRBs over a broad energy range spanning about 7 decades of gammaray energy. In September 2008, Fermi observed the exceptionally luminous GRB 080916C, with the largest apparent energy release yet measured. The high-energy gamma rays are observed to start later and persist longer than the lower energy photons. A simple spectral form fits the entire GRB spectrum, providing strong constraints on emission models. The known distance of the burst enables placing lower limits on the bulk Lorentz factor of the outflow and on the quantum gravity mass.

Coenzyme Q system in the classification of some ascosporogenous yeast genera in the families Saccharomycetaceae and Spermophthoraceae.

The Co-Q systems of 11 strains representing the genera Schwanniomyces, Lodderomyces, Lipomyces, Nematospora and Metschnikowia were determined. All the genera were characterized by the Q-9 system except for the genus Nematospora with needle-shaped ascospores. The only species, Nem. coryli, was found to have the Q-6 system. These results are discussed from the taxonomic point of view.

A study of temporomandibular joint sounds. Part 2. Acoustic characteristics of joint sounds.

In an attempt to gain a better understanding of temporomandibular joint (TMJ) sounds, we recorded joint sounds from 14 non-orthodontically treated dental students, analyzed the acoustic characteristics of the TMJ sounds, and correlated the sound characteristics with axiographic features, morphologic observations of X-ray images and clinical history. The group with a low peak frequency (< 500 Hz) of the opening click had a shorter history of subjective joint sound, a longer distance between the opening and closing curves, and a low rate of TMJ transformation. For the closing click, the history of subjective joint sounds tended to be longer when the duration of the wave was short. Acoustic analysis of TMJ sounds could be an aid to the differential diagnosis of temporomandibular disorders, although it is difficult to deduce the clinical history and internal deformities of the TMJ based solely on acoustic characteristics.