Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of shock, multi-organ failure, and high mortality. In Japan, appropriate notification ...measures based on the Infectious Disease Control law are mandatory for cases of STSS caused by β-haemolytic streptococcus. STSS is mainly caused by group A streptococcus (GAS). Although an average of 60–70 cases of GAS-induced STSS are reported annually, 143 cases were recorded in 2011. To determine the reason behind this marked increase, we characterized the emm genotype of 249 GAS isolates from STSS patients in Japan from 2010 to 2012 and performed antimicrobial susceptibility testing. The predominant genotype was found to be emm1, followed by emm89, emm12, emm28, emm3, and emm90. These six genotypes constituted more than 90% of the STSS isolates. The number of emm1, emm89, emm12, and emm28 isolates increased concomitantly with the increase in the total number of STSS cases. In particular, the number of mefA-positive emm1 isolates has escalated since 2011. Thus, the increase in the incidence of STSS can be attributed to an increase in the number of cases associated with specific genotypes.
There are growing efforts to control thermal transport via coherent phonons in one-dimensional superlattices. Typically, the difference in intrinsic lattice structures of the constituent materials ...generates an interface disorder during the fabrication process, limiting the coherent phonon transport manipulation. On the other hand, flexible integration and atomistic interlayer smoothness of a van der Waals (vdW) heterostructure provide an ideal platform for coherent phonon transport manipulations. Toward the ultimate goal of designing small thermal-conductivity materials at room temperature, herein we investigate the controllability of coherent phonon transport in vdW graphene-MoS2 heterostructures with different stacking orders using non-equilibrium molecular dynamics simulations. Using Bayesian optimization–based materials informatics, the optimal stacking order of graphene and MoS2 is efficiently identified from tens of thousands of candidates with varying degrees of phonon localization. The obtained thermal conductivity of the optimized heterostructure (0.026 W/m-K) is significantly lower than that of its building blocks (pristine MoS2 and graphene). Additionally, the optimized heterostructure has a thermal conductivity lower than those of representative low thermal conductivity solid materials (amorphous and disordered crystals), and the amorphous polymers. The underlying physical mechanism of coherent phonon localization is uncovered by calculating the phonon transmission in the optimum heterostructure and analyzing the histogram distribution pattern of the phonon transmissions in different disordered stacking heterostructures. The presence of localization is further validated by a comparative study of the optimum heterostructure to pristine graphene with introduced defects, changed the thickness and temperature of the system. Our work provides insight into the coherent phonons transport behavior in the atomistically smooth vdW structure, which is essential for further development of phononics.
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•Thermal metamaterial with ultralow thermal conductivity (0.026 W/m-K).•The optimum graphene-MoS2 heterostructure is determined by the Bayesian optimization–based materials informatics.•Phonon-transmission histogram analysis identifies significant phonon localization.•The defects and thickness effect further validate the presence of phonon localization.
Scrub typhus ('Tsutsugamushi' disease in Japanese) is a mite-borne infectious disease. The causative agent is Orientia tsutsugamushi, an obligate intracellular bacterium belonging to the family ...Rickettsiaceae of the subdivision alpha-Proteobacteria. In this study, we determined the complete genome sequence of O. tsutsugamushi strain Ikeda, which comprises a single chromosome of 2 008 987 bp and contains 1967 protein coding sequences (CDSs). The chromosome is much larger than those of other members of Rickettsiaceae, and 46.7% of the sequence was occupied by repetitive sequences derived from an integrative and conjugative element, 10 types of transposable elements, and seven types of short repeats of unknown origins. The massive amplification and degradation of these elements have generated a huge number of repeated genes (1196 CDSs, categorized into 85 families), many of which are pseudogenes (766 CDSs), and also induced intensive genome shuffling. By comparing the gene content with those of other family members of Rickettsiacea, we identified the core gene set of the family Rickettsiaceae and found that, while much more extensive gene loss has taken place among the housekeeping genes of Orientia than those of Rickettsia, O. tsutsugamushi has acquired a large number of foreign genes. The O. tsutsugamushi genome sequence is thus a prominent example of the high plasticity of bacterial genomes, and provides the genetic basis for a better understanding of the biology of O. tsutsugamushi and the pathogenesis of 'Tsutsugamushi' disease.
Surveillance of
Streptococcus pneumoniae
serotypes is important for the successful implementation of vaccination strategies to prevent the spread of invasive pneumococcal diseases. The standard ...method of serotyping of pneumococcal isolates is the phenotypic Neufeld test, which is cost- and labor-intensive. Recently, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been implemented as a rapid, simple and inexpensive method for identifying species. We evaluated the performance of MALDI-TOF MS for serotyping ten major serotypes of
S. pneumoniae
in Japan (serotypes 3, 6B, 15A, 15C, 19A, 19 F, 23A, 24 F, 35B and 38) using the Biotyper and ClinProTools. After optimizing the settings, we validated their serotyping performance for serotypes 3, 15A and 19A using a separate set of isolates that were not used in the creation of the classification algorithms. A total of 574 isolates of
S. pneumoniae
collected from Japanese nationwide surveillance studies were included. Of these, 407 isolates belonged to the ten major serotypes. Biotyper and ClinProTools correctly identified 77.9 % and 84.0 %, respectively, of the ten major serotype isolates. The validation analysis included a total of 113 isolates of the serotypes 3, 15A and 19A isolates. Biotyper and ClinProTools correctly identified 85.0 % and 69.9 % of the validation cohort isolates, respectively. MALDI-TOF MS has the potential to discriminate the ten major
S. pneumoniae
serotypes prevalent in Japan.
We propose a new energy estimator to determine the energies of gamma-ray induced air showers based on the lateral distribution of extensive air showers in the energy range between 10 TeV and 1000 ...TeV. We carry out a detailed Monte Carlo simulation assuming the Tibet air shower array located at an altitude of 4,300 m above sea level. We define S50, which denotes the particle density at 50 m from the air shower axis, as a new energy estimator. Using S50, the energy resolution is estimated to be approximately 16 % at 100 TeV in the range of the zenith angle
𝜃
< 20
∘
. We find S50 giving a better energy resolution than 27 % for the air shower size (
N
e
) and 30 % for the sum of detected particles (
∑
ρ
), which have been used so far, at 100 TeV. We also compare the reconstructed age distributions of gamma-ray induced air showers and hadronic cosmic-ray induced air showers. The age parameter may help to discriminate between primary gamma rays and hadronic cosmic rays.
To characterise the dissemination patterns of uropathogenic Escherichia coli (UPEC) in a community, we conducted a study utilising molecular and fundamental descriptive epidemiology. The subjects, ...consisted of women having community-acquired acute urinary tract infection (UTI), were enrolled in the study from 2011 to 2012. UPEC isolates were subjected to antibacterial-susceptibility testing, O serogrouping, phylotyping, multilocus-sequence typing with phylogenetic-tree analysis and pulsed-field-gel electrophoresis (PFGE). From the 209 unique positive urinary samples 166 UPEC were isolated, of which 129 were fully susceptible to the tested antibiotics. Of the 53 sequence types (STs), the four most prevalent STs (ST95, ST131, ST73 and ST357) accounted for 60% of all UPEC strains. Antimicrobial resistance was less frequently observed for ST95 and ST73 than for the others. A majority of rare STs and a few common STs constituted the diversity pattern within the population structure, which was composed of the two phylogenetically distinct clades. Eleven genetically closely related groups were determined by PFGE, which accounted for 42 of the 166 UPEC isolates, without overt geo-temporal clustering. Our results indicate that a few major lineages of UPEC, selected by unidentified factors, are disseminated in this community and contribute to a large fraction of acute UTIs.
Idiopathic pulmonary fibrosis (IPF) is a fatal disease with a median survival of 3-4 years after diagnosis. It is the most frequent form of a group of interstitial pneumonias of unknown etiology. ...Current available therapies prevent deterioration of lung function but no therapy has shown to improve survival. Periostin is a matricellular protein of the fasciclin 1 family. There is increased deposition of periostin in lung fibrotic tissues. Here we evaluated whether small interfering RNA or antisense oligonucleotide against periostin inhibits lung fibrosis by direct administration into the lung by intranasal route. Pulmonary fibrosis was induced with bleomycin and RNA therapeutics was administered during both acute and chronic phases of the disease. The levels of periostin and transforming growth factor-β1 in airway fluid and lung tissue, the deposition of collagen in lung tissue and the lung fibrosis score were significantly reduced in mice treated with siRNA and antisense against periostin compared to control mice. These findings suggest that direct administration of siRNA or antisense oligonucleotides against periostin into the lungs is a promising alternative therapeutic approach for the management of pulmonary fibrosis.
Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of shock, multiorgan failure, and high mortality. Although STSS is mainly caused by ...Streptococcus pyogenes, group G streptococcus identified as S. dysgalactiae subsp. equisimilis (SDSE) causing STSS has also been reported; however, no study has analyzed >100 isolates of SDSE causing STSS. Therefore, we characterized the emm genotype of 173 SDSE isolates obtained from STSS patients in Japan during 2014–2016 and performed antimicrobial susceptibility testing using the broth microdilution method and emm gene typing. The predominant emm genotype was found to be stG6792, followed by stG485, stG245, stG10, stG6, and stG2078. These six genotypes constituted more than 75% of the STSS isolates. The proportion of each emm genotype in STSS isolates correlated with that in invasive isolates previously reported. We found that 16.2% of the isolates showed clindamycin resistance. The proportion of clindamycin-resistant SDSE isolates was significantly higher than that of S. pyogenes isolates. Thus, while treating STSS caused by SDSE, it is necessary to consider the possibility of clindamycin resistance and to ensure judicious use of the drug.
The gastrointestinal absorption of phenytoin (PHT), an antiepileptic drug, is often affected by its interaction with co-administered enteral nutrients through a nasogastric (NG) tube, resulting in ...decreased plasma PHT concentration. In this study, we measured the recovery rate (%) of
PHT (Aleviatin® powder) passed through an NG tube when co-administered with distilled water or enteral nutrients (F2α®, Racol® NF, Ensure Liquid® and Renalen® LP). We also measured plasma PHT levels in
rats, after oral co-administration of PHT with enteral nutrients. We demonstrate that PHT recovery rate was close to 100 % in all cases after passage through the NG tube. In the rat study, the AUC0→∞ of PHT concentration after oral administration significantly decreased
when it was co-administered with F2α® and Racol® NF compared to distilled water. However, the AUC0→∞ of PHT was unchanged when co-administered with F2α® 2 h after initial PHT administration. We therefore
conclude that the co-administration of PHT with F2α® and Racol® NF caused a reduction in the absorption of PHT from the gastrointestinal tract to the blood, without adsorption to the NG tube. The administration of enteral nutrients 2 h after PHT is
one clear way to prevent a decrease in plasma PHT concentration.
Abstract
The Tibet ASγ group has been continuously observing cosmic rays and cosmic gamma rays above several TeV using the muon detector array (MD) and high-density Tibet air-shower array (Tibet-III) ...installed on the Tibet plateau at an altitude of 4300 m. The MD is a water Cherenkov pool array with a large effective area of 3400 m2 and has an excellent capability of primary selection using the number of muons in the shower. We report the sensitivity of the proton spectrum measurements for energies 40–630 TeV obtained via Monte Carlo simulations for an air-shower experiment. It was found that protons could be separated with a purity of 90%, and the survival ratio of protons including model dependence was 14.2%–19.1% and 3.7%–7.4% at about 35 TeV and about 450 TeV, respectively. The maximum total systematic error of the proton flux depending on interaction models in air-shower development and composition models was ±37%. With a large effective area and high proton separation capability, the Tibet ASγ experiment can measure the proton spectrum in the energy range from tens to hundreds of TeV with high statistical accuracy.
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