16S rRNA gene-based metagenomic analysis reveals differences in bacteria-derived extracellular vesicles in the urine of pregnant and non-pregnant women

Recent evidence has indicated that bacteria-derived extracellular vesicles (EVs) are important for host–microbe communication. The aims of the present study were to evaluate whether bacteria-derived EVs are excreted via the urinary tract and to compare the composition of bacteria-derived EVs in the urine of pregnant and non-pregnant women. Seventy-three non-pregnant and seventy-four pregnant women were enrolled from Dankook University and Ewha Womans University hospitals. DNA was extracted from urine EVs after EV isolation using the differential centrifugation method. 16S ribosomal RNA (16S rRNA) gene sequencing was performed using high-throughput 454 pyrosequencing after amplification of the V1–V3 region of the 16S rDNA. The composition of 13 taxa differed significantly between the pregnant and non-pregnant women. At the genus level, Bacillus spp. EVs were more significantly enriched in the urine of the pregnant women than in that of the non-pregnant women (45.61% vs 0.12%, respectively). However, Pseudomonas spp. EVs were more dominant in non-pregnant women than in pregnant women (13.2% vs 4.09%, respectively). Regarding the compositional difference between pregnant women with normal and preterm delivery, EVs derived from Ureaplasma spp. and the family Veillonellaceae (including Megasphaera spp.) were more abundant in the urine of preterm-delivered women than in that of women with normal deliveries. Taken together, these data showed that Bacillus spp. EVs predominate in the urine of pregnant women, whereas Pseudomonas spp. EVs predominate in the urine of non-pregnant women; this suggests that Bacillus spp. EVs might have an important role in the maintenance of pregnancy.     

Efficient methods for isolating five phytochemicals from Gentiana macrophylla using high‐performance countercurrent chromatography

Efficient high‐performance countercurrent chromatography methods were developed to isolate five typical compounds from the extracts of Gentiana macrophylla. n‐Butanol‐soluble extract of G. macrophylla contained three hydrophilic iridoids, loganic acid ( 1 ), swertiamarin ( 2 ) and gentiopicroside ( 3 ), and a chromene derivative, macrophylloside D ( 4 ) which were successfully isolated by flow rate gradient (1.5 mL/min in 0–60 min, 5.0 mL/min in 60–120 min), and consecutive flow rate gradient HPCCC using n‐butanol/0.1% aqueous trifluoroacetic acid (1:1, v/v, normal phase mode) system. The yields of 1 – 4 were 22, 16, 122, and 6 mg, respectively, with purities over 97% in a flow rate gradient high‐performance countercurrent chromatography, and consecutive flow rate gradient high‐performance countercurrent chromatography gave 1 , 2 , 3 (54, 41, 348 mg, respectively, purities over 97%) and 4 (13 mg, purity at 95%) from 750 mg of sample. The main compound in methylene chloride soluble extract, 2‐methoxyanofinic acid, was successfully separated by n‐hexane/ethyl acetate/methanol/water (4:6:4:6, v/v/v/v, flow‐rate: 4 mL/min, reversed phase mode) condition. The structures of five isolates were elucidated by ¹H, ¹³C NMR and ESI‐Q‐TOF‐MS spectroscopic data which were compared with previously reported values.     

The structure of the π-molecular complex between 1,4-dihydro-9,10-anthrahydroquinone and 1,4-dihydro-9,10-anthraquinone

The structure of the π-molecular complex (10) was assigned on the basis of the solid state¹³C-nmr spectrum. The solid state¹³C-nmr spectrum of quinhydrone (12) has also been determined. Accurate¹H and¹³C chemical shift assignments have been made for the compounds3,5,6,7,8, and10 on the basis of HMQC and HMBC spectral data. The π-molecular complex10 crystallizes in the space groupP2₁ In with cell parameters:a=4.052 (1) Å,b=6.477 (1) Å,c=19.093 (2) Å, β=90.17 (1)^o,z=1,D _c =1.400 g mc^?32. Crystal and molecular structure of the title compound, C₂₈H₂₂O₄, has been determined by an X-ray analysis of10 by direct methods from diffractometer data and refined by full-matrix least-squares     

Abnormal nuclear matter and many-body forces

Qualitative aspects of quantum corrections to the Lee-Wick abnormal nuclear matter are studied in terms of many-body forces in the normal nuclear matter implied by the σ-model Lagrangian field theory. Using a simplified model for the scalar meson self-energy in the nuclear medium and restricting to a set of graphs which in non-relativistic normal nuclear matter reduces to the well-known random phase approximation (RPA), we have found that an abnormal nuclear state can be bound or unbound depending upon whether strongly attractive multi-body forces are present or absent in the normal matter. This is in support of our previous result obtained heuristically from some general considerations of quantum corrections. A strongly bound abnormal matter with an equilibrium density of a few times the normal nuclear matter density ρ₀ can be formed if large attractive manybody forces can be accommodated in the normal nuclear matter. However if one accepts the present status of theories of nuclear matter binding energy in which no attractive many-body forces are called for, then the abnormal state can occur only at large densities (perhaps 8 to 10 times ρ₀) and is expected to be unbound by several hundred MeV per particle.     

Relaxation properties of some segmented polyurethane-CaCO3 composites. A Dielectric study

Dielectric relaxation in three segmented polyurethane-CaCO₃ composites was investigated between ?70°C and +150°C in the 300 Hz to 100 kHz frequency range. Two of the polymers contained a polyacetal-polyether soft segment, whereas the soft component of the third polymer was polypropylene oxide. The hard segments consisted of 4,4′-diphenyl methane diisocyanate in two cases and toluene-2,4-diisocyanate in the third case. In parallel studies two calorimetric relaxations, designated α and α′, were observed for each sample and were determined to be glass transitions of the soft and hard segments, respectively. In general, the transition temperatures decrease with increasing filler content. High frequency, low temperature permittivities increase while low frequency, high temperature AC conductivities generally decrease with increasing filler content. The shift in the transition temperatures can be explained using the adsorption theory of filler-polymer interactions and the densities of the samples. The interfacial polarization mechanism becomes important only above the α′ transition temperature and below 1 kHz.     

Velocity dependence of the nucleon-nucleon interaction,exchange currents and enhancement of the dipole sum rule in nuclei

A model is employed to describe the velocity dependence of the effective nucleon-nucleon interaction in nuclear matter. The interactions in this model consist of π^? and ρ-meson exchange, together with short-range correlations induced by the strongly repulsive potential resulting from ω-meson exchange. With known coupling strengths, these interactions produce an effective mass $\text{m}{}^1\text{/m = 0.75}$ in nuclear matter.Through the formalism of Fermi liquid theory, the exchange-current correction to the orbital g-factor, δg_l, can be described in terms of the velocity dependence in the neutron-proton interaction, and, within the model, this can be related to the effective mass $\text{m}{}^1$. With $\text{m}{}^1\text{/m = 0.75}$, the δg_l for the proton turns out to be 0.22, 45% of it coming from π-meson exchange.Additional contributions to $\text{m}{}^1\text{/m}$ in nuclei come from the coupling of vibrations to quasiparticles; these are especially important in the nuclear surface, and tend to increase the effective mass, when averaged over both nuclear volume and surface, so that $\text{〈m}{}^1\text{/m〉}{}_{\mathrm{<mtext>av.</mtext>}}\text{? 1}$. In so far as these contributions arise from isovector vibrations, we can use the same model as for π- and ρ-meson exchange, and show that the same relation between $\text{m}{}^1\text{/m}$ and δg_l holds, so that for $\text{〈m}{}^1\text{/m〉}{}_{\mathrm{<mtext>av.</mtext>}}\text{= 1}$, δg_l = 0. The contributions from coupling to vibrations will depend upon the single-particle state, however; states of high-angular momentum will tend to have $\text{〈m}{}^1\text{/m〉}{}_{\mathrm{<mtext>av.</mtext>}}\text{< 1}$ and δg_l > 0.Finally, the enchancement δg_l in gl can be connected with the enhancement k in the dipole sum rule originating from the giant-resonance region. This connection is not very precise, but gives a small positive κ ～ 0.2.     

An ultrasonic method for measuring the elastic properties of human tibial cortical and cancellous bone

Ultrasonic techniques have been used to measure the elastic properties of bone. Eight human tibiae were used to determine and map the elastic properties of cortical and cancellous bone. The present study shows cortical bone to be at least orthotropic in its material symmetry. The mechanical properties of cortical bone are more homogeneous along the length than around the circumference. The variations in the properties around the quadrant of cortical bone are small, less than 10%, while differences in the properties around the circumference of cancellous bone are more apparent, approximately 5 times those of cortical bone. The elastic properties of cancellous bone exhibited inhomogeneity and some consistency pattern along both the length and the circumference.     

Kaon cloud and baryon magnetic moments

The kaon cloud correction to the magnetic moments of the octet baryons that arises when chiral SU(2) × SU(2) symmetry is enlarged to SU(3) × SU(3) is calculated in the chiral bag model. The effect is considerably smaller than the pion cloud effect provided the bag radius is R ? 1 fm. We discuss the implications of this result on our ongoing attempt to incorporate chiral symmetry into the bag model of the nucleon and on the scale sizes associated with (nearly) massless quarks and massive quarks.