Search

Massive Black Hole (MBH) binaries are considered to be one of the most important sources of Gravitational Waves (GW) that can be detected by GW detectors like LISA. However, there are a lot of uncertainties in the dynamics of MBH binaries in the stages leading up to the GW-emission phase. It has been recently suggested that Nuclear Star Clusters (NSCs) could provide a viable route to overcome the final parsec problem for MBH binaries at the center of galaxies. NSCs are collisional systems where the dynamics would be altered by the presence of a mass spectrum. In this study, we use a suite of high-resolution $N$-body simulations with over 1 million particles to understand how collisional relaxation under the presence of a mass spectrum of NSC particles affects the dynamics of the MBH binary under the merger of two NSCs. We consider MBH binaries with different mass ratios and additional non-relaxed models. We find that mass-segregation driven by collisional relaxation can lead to accelerated hardening in lower mass ratio binaries but has the opposite effect in higher mass ratio binaries. Crucially, the relaxed models also demonstrate much lower eccentricities at binary formation and negligible growth during hardening stages leading to longer merger timescales. The results are robust and highlight the importance of collisional relaxation on changing the dynamics of the binary. Our models are state-of-the-art, use zero softening, and high enough particle numbers to model NSCs realistically., Comment: 18 pages, 14 figures. New version with higher resolution simulations. Accepted in MNRAS

We explore the nature of low surface brightness galaxies (LSBGs) in the hydrodynamic cosmological simulation TNG100 of the IllustrisTNG project, selecting a sample of LSBGs ($r$-band effective surface brightness $μ_r > 22.0$ mag arcsec$^{-2}$) at $z=0$ over a wide range of stellar masses ($M_{\ast} = 10^{9}$-$10^{12}$ M$_\odot$). We find LSBGs of all stellar masses, although they are particularly prevalent at $M_{\ast} < 10^{10}$ M$_\odot$. We show that the specific star formation rates of LSBGs are not significantly different from those of high surface brightness galaxies (HSBGs) but, as a population, LSBGs are systematically less massive and more extended than HSBGs, and tend to display late-type morphologies according to a kinematic criterion. At fixed stellar mass, we find that haloes hosting LSBGs are systematically more massive and have a higher baryonic fraction than those hosting HSBGs. We find that LSBGs have higher stellar specific angular momentum and halo spin parameter values compared to HSBGs, as suggested by previous works. We track the evolution of these quantities back in time, finding that the spin parameters of the haloes hosting LSBGs and HSBGs exhibit a clear bifurcation at $z \sim 2$, which causes a similar separation in the evolutionary tracks of other properties such as galactic angular momentum and effective radius, ultimately resulting in the values observed at $z =$ 0. The higher values of specific stellar angular momentum and halo spin in LSBGs seem to be responsible for their extended nature, preventing material from collapsing into the central regions of the galaxies, also causing LSBGs to host less massive black holes at their centres., 14 pages, 10 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society

Supermassive black holes (SMBHs) of $\sim 10^9\, \rm M_{\odot }$ are generally believed to be the central engines of the luminous quasars observed at z ≳ 6, but their astrophysical origin remains elusive. To investigate the formation of these distant quasars, we perform a suite of zoom-in simulations on a favourable halo, with a mass of $\sim 10^{13}\, \rm M_{\odot }$ at z = 6 and a history of multiple major mergers, ideal for BH growth. We test BH seeds of $10 {\!-\!} 10^6\, \rm M_{\odot }$, and various accretion and feedback models, including thin-disc and slim-disc accretion. We find that abundant gas supply and efficient angular momentum transport by gravitational torques are critical to BH accretion, and that the final BH mass depends strongly on the seed mass and radiative efficiency which in turn depends on feedback model. In our simulations, heavy seeds of $\gtrsim 10^4\, \rm M_{\odot }$ can grow rapidly to SMBHs of $10^8 {\!-\!} 10^9\, \rm M_{\odot }$ by z ∼6 in both thin and slim disc accretion models, provided that the duty cycle of near-Eddington accretion with an Eddington ratio λEdd ≳ 0.6 is maintained at $\gtrsim 40{{\ \rm per\ cent}}$. In particular, for a $10^5\, \rm M_{\odot }$ seed, both our fiducial model and the supercritical accretion model with no spin produce bright quasars with SMBHs of $\sim 10^9\, \rm M_{\odot }$ at z ∼ 7.5. On the other hand, the light seeds of $\lesssim 10^3\, \rm M_{\odot }$ failed to grow to $10^8\, \rm M_{\odot }$ by z ∼ 6 in our simulations. We caution that the results are inconclusive due to limitations of our numerical methods and physical models, and we stress the need for further investigations on the growth of BH seeds with more advanced methods.

Here we describe the self-assembly of an achiral molecule into macroscopic helicity as well as the emergent chirality selective spin filtering effect. It was found that benzene-1,3,5-tricarboxamide (BTA) motif with an aminopyridine group in each arm could coordinate with Ag(I) and self-assemble into nanospheres. Upon sonication symmetry breaking occurred and the nanospheres transfer into helical nanofibers with strong CD signals. Although the sign of the CD signals appeared randomly, it could be controlled by using the as-made chiral assemblies as a seed. Furthermore, it was found that the charge transport of the helical nanofibers was highly selective with a spin-polarization transport of up to 45% although the chiral nanofibers are composed exclusively from achiral building blocks. The work demonstrated a new example of the symmetry breaking under sonication and the chirality selective spin filtering effect.

This study aimed to understand the epidemiological and clinical characteristics of pediatric SARS-CoV-2 infection during the early stage of Omicron variant outbreak in Shanghai.This study included local COVID-19 caseslt;18 years in Shanghai referred to the exclusively designated hospital from March 7 to March 31, 2022. Clinical data, epidemiological exposure, and COVID-19 vaccination status were collected. Relative risks (RRs) were calculated to assess the effect of vaccination on symptomatic infection and febrile disease.A total of 376 pediatric cases of COVID-19 (median age: 6.0 ± 4.2 years) were referred to the designated hospital, including 257 (68.4%) symptomatic cases and 119 (31.6%) asymptomatic cases. Of the 307 (81.6%) children ≥3 years eligible for COVID-19 vaccination, 110 (35.8%) received two doses of vaccines. The median interval between the completion of two-dose vaccination and infection was 3.5 (interquartile range [IQR]: 3, 4.5) months. Compared with no vaccination, two-dose COVID-19 vaccination reduced the risks of symptomatic infection and febrile disease by 35% (RR 0.65, 95% confidence interval [CI]: 0.53-0.79) and 33% (RR 0.64, 95% CI: 0.51-0.81) among confirmed cases. Eighty-four percent of symptomatic cases had fever (mean duration: 1.7 ± 1.0.8 days), 40.5% had cough, and 16.4% had transient leukopenia. Three hundred and seven (81.6%) had an epidemiological exposure in household (69.1%), school (21.8%), and residential area (8.8%).The surge of pediatric COVID-19 cases and multiple transmission model reflect wide dissemination of Omicron variant in the community. Asymptomatic infection is common among Omicron-infected children. COVID-19 vaccination can offer some protection against symptomatic infection and febrile disease.

Objectives: To understand the epidemiological and clinical characteristics of pediatric SARS-CoV-2 infection during the early stage of Omicron variant outbreak in Shanghai. Study designs: This study included local COVID-19 cases

ObjectivesTo understand the epidemiological and clinical characteristics of pediatric SARS-CoV-2 infection during the early stage of Omicron variant outbreak in Shanghai.MethodsThis study included local COVID-19 cases ResultsA total of 376 pediatric cases of COVID-19 (median age:6.0±4.2 years) were referred to the designated hospital during the period of March 7-31, including 257 (68.4%) symptomatic cases and 119 (31.6%) asymptomatic cases. Of the 307 (81.6%) children;3 years eligible for COVID-19 vaccination, 110 (40.4%) received 2-dose vaccines and 16 (4.0%) received 1-dose vaccine. The median interval between 2-dose vaccination and infection was 3.5 (IQR: 3, 4.5) months (16 days-7 months). Two-dose COVID-19 vaccination reduced the risks of symptomatic infection and febrile disease by 35% (RR 0.65, 95% CI:0.53-0.79) and 33% (RR 0.64, 95% CI: 0.51-0.81). Two hundred and sixteen (83.4%) symptomatic cases had fever (mean duration: 1.7±1.0.8 days), 104 (40.2%) had cough, 16.4% had transient leukopenia; 307 (81.6%) had an epidemiological exposure in household (69.1%), school (21.8%) and residential area (8.8%).ConclusionThe surge of pediatric COVID-19 cases and multiple transmission model reflect wide dissemination of Omicron variant in the community. Asymptomatic infection is common among Omicron-infected children. COVID-19 vaccination can offer protection against symptomatic infection and febrile disease.

Squaraine dyes are well known for their strong absorption in the visible regime. Reports on chiral squaraine dyes are, however, scarce. To address this gap, we here report two novel chiral squaraine dyes and their achiral counterparts. The presented dyes are aggregated in solution and in thin films. A detailed chiroptical study shows that thin films formed by co‐assembling the chiral dye with its achiral counterpart exhibit exceptional photophysical properties. The circular dichroism (CD) of the co‐assembled structures reaches a maximum when just 25 % of the chiral dye are present in the mixture. The solid structures with the highest relative CD effect are achieved when the chiral dye is used solely as a director, rather than the structural component. The chiroptical data are further supported by selected spin‐filtering measurements using mc‐AFM. These findings provide a promising platform for investigating the relationship between the dissymmetry of a supramolecular structure and emerging material properties rather than a comparison between a chiral molecular structure and an achiral counterpart., Helicity control: An unexpected outcome of the co‐assembly of achiral squaraine dye a‐SQ‐1 with its chiral counterpart S ‐SQ‐1 is reported. A maximum in optical activity is observed in the supramolecular aggregates of a 3:1 mixture with a‐SQ‐1 as the major component. Intriguingly, the highest spin‐selective electron transport is observed for this mixing ratio as well, illustrating the direct relationship between optical activity and spin‐selective electron transport.

Significance In contrast to conventional electronics, spintronics devices exploit the electron spin as an additional degree of freedom. The chirality-induced spin selectivity (CISS) effect, in which chiral molecules act as spin filters in electron transport, provides a pathway to control spins in molecules. We describe an approach that integrates both spin-polarizing and spin-propagating functionality into organic structures that feature low charge transport resistances. Binding chiral ligands to molecular wires controls polarized spin handedness, regulates spin currents, generates large NIR rotational strengths, and provides a mechanism to flip the favored spin orientation for spin transmission through chiral organic molecules. This work points the way to materials that provide both high spin selectivity and large-magnitude spin currents via the CISS mechanism.

We report on the synthesis and self-assembly of 2,15- and 4,13-disubstituted carbo[6]helicenes 1 and 2 bearing 3,4,5-tridodecyloxybenzamide groups. The self-assembly of these [6]helicenes is strongly influenced by the substitution pattern in the helicene core that affects the mutual orientation of the monomeric units in the aggregated form. Thus, the 2,15-substituted derivative 1 undergoes an isodesmic supramolecular polymerization forming globular nanoparticles that maintain circularly polarized light (CPL) with glum values as high as 2 × 10−2. Unlike carbo[6]helicene 1, the 4,13-substituted derivative 2 follows a cooperative mechanism generating helical one-dimensional fibers. As a result of this helical organization, [6]helicene 2 exhibits a unique modification in its ECD spectral pattern showing sign inversion at low energy, accompanied by a sign change of the CPL with glum values of 1.2 × 10−3, thus unveiling an example of CPL inversion upon supramolecular polymerization. These helical supramolecular structures with high chiroptical activity, when deposited on conductive surfaces, revealed highly efficient electron-spin filtering abilities, with electron spin polarizations up to 80% for 1 and 60% for 2, as measured by magnetic conducting atomic force microscopy.

BACKGROUND & AIMS: Chronic hepatitis B (CHB) virus infection is a major cause of morbidity and mortality. We aim to investigate the association between hepatic histology and clinical characteristics in asymptomatic treatment-naïve children chronically infected with hepatitis B virus (HBV) in Shanghai China. METHODS: Liver biopsies of 278 asymptomatic treatment-naïve children with chronic hepatitis B virus infection were scored for inflammation and fibrosis, and correlated with clinical and laboratory data. RESULTS: The clinical, virologic and pathologic features of chronic HBV infection were studied in 278 treatment-naïve children from Shanghai, China, of who were all asymptomatic. And 177 (63.7%) of the children were male. Sera from mothers of 277 of these children were HBsAg positive. Up to 87.4% of subjects were hepatitis B e antigen-positive at the time of the biopsy. The median age at biopsy was 5.1 years (interquartile range 2.8-8.4 years). HBV DNA levels were generally high (mean 7.4 log10 IU/mL), as was serum alanine aminotransferase (median 105 U/L). Using the Ishak-modified histology activity index scoring system, no inflammation was seen in 2.9% cases, mild inflammation was in 22.3%, moderate in 73.4%, and severe in 1.4%. No fibrosis was seen in 11.5%, mild fibrosis in 32.7%, moderate fibrosis in 47.5%, and cirrhosis in 8.3%. When serum ALT level was < 80 (2×ULN) and > 80 U/L, the degree of inflammation (PP<3 and >3 years (P<3 years at biopsy. No correlation was found between histological changes with gender, HBV genotypes or HBV DNA levels. CONCLUSION: Significantly wide range of inflammation and fibrosis is seen in asymptomatic treatment-naïve children with chronic hepatitis B in Shanghai China. Serum ALT >80 U/L may be a strong indicator of the degree of hepatic inflammation and severity of fibrosis. Moderate fibrosis and cirrhosis has already appeared in aged <3 years children.

Studying the self-assembly behavior of DNA origami allows a better understanding of molecular assembly characteristics at the nanoscale. Presently, the mechanisms governing growth and dynamics of DNA origami assembly are still not very clear and there is a lack of direct visualization of the growth processes on the long single-strand scaffold. Here, we investigate the kinetics, especially the real-time seeding growth process of six special designs of 2D DNA origami at room temperature (RT) without the assistance of denaturing chemicals. The prealignment of single-strand long scaffold and logical seeding growth behaviors are revealed during the growth process at RT. Furthermore, we studied the thermal stability of the DNA nanostructures under limited structural defects. Revealed characteristics of seeding growth can be used to build large and complex DNA nanodevices capable of performing logical operations with nanometer precision.

International audience; We report a study of alpha-[P2W18O62]6-, Wells-Dawson polyoxometalate layers deposited on ITO coated glass substrates. A variety of techniques has been used including atomic force microscopy for surface topography characterization, current mapping and current-voltage characteristics, X-ray photoemission spectroscopy for chemical analysis, UV-visible photoemission spectroscopy for determination of band line-ups and energy dispersive X-ray reflectivity for determination of layer thicknesses and scattering length densities. The conditions of film deposition and subsequent thermal annealing strongly affect the film characteristics. In particular, we show that nanostriped films a few tens of nm thick can be obtained in a reproducible manner and that such structuring is accompanied by the appearance of gap-states and by a switch from an insulating to a conductive state. Current-voltage characteristics demonstrate that highly ordered films of K 6 [P 2 W 18 O 62 ] allow electron flow only from ITO to [P2W18O62]6-, thus showing a rectifying effect. Finally, we integrate the POM layer 2 into an organic photovoltaic device and show the conduction through it thanks to favorable band alignment between ITO, the gap states and the active photovoltaic layers.

Granular sludge is considered as a promising technology for wastewater treatment owing to the high biomass retention and excellent settleability. In this study, the formation and underlying mechanisms of granular sludge for stable and efficient nitrite accumulation in glycerol-driven partial denitrification (PD) reactors were investigated. The PD granular sludge (PDGS) was successfully formed with developing and mature stages. The mature PDGS exhibited superior settleability (mean particle size: 468.1 μm, and SVI5:16.4 mL/g SS), and high microbial activity (VSS/SS: 0.80–0.92). The nitrite was stably and efficiently accumulated with an average nitrate-to nitrite transformation ratio of 87.3%. Morphological analysis showed that the mature granules were dominated by cocci and exhibited compact structure with few inorganic components. The proteins (i.e. tyrosine, tryptophan and aromatic protein-like substances) in tightly-bound extracellular polymeric substances (EPS) were expected to play critical roles in the granulation process in view of their good correlation with particle size variation. The EPS contents (mainly polysaccharides and proteins) and living cells were distributed throughout the granule, suggesting the overall high stability and bioactivity of formed PDGS. Moreover, the glycerol-driven PD reactor caused the evident evolution of microbial structure, and the significant enrichment of Saccharibacteria was expected to be responsible for the granulation process, which was increased to 66.6% in the matured sludge. This study confirmed the feasibility and superior performance of PDGS fed with glycerol.

ART$^2$ is a 3D multi-wavelength Monte Carlo radiative transfer (RT) code that couples continuum and emission lines to track the propagation of photons and their interactions with the interstellar medium (ISM). The previous version of ART$^2$, which included continuum and Ly$\alpha$ line, has been extensively applied to hydrodynamics simulations to study multi-band properties of galaxies and ISM. Here, we describe new implementations of non-local thermodynamic equilibrium RT of molecular and atomic fine structure emission lines, and the parallelization of the code using a number of novel methods. The new ART$^2$ can efficiently and self-consistently produce a full spectrum that includes both continuum and lines such as [CII], [NII], [OIII], Ly$\alpha$, and CO. These essential features, together with the multi-phase ISM model and the adaptive grid, make ART$^2$ a multi-purpose code to study multi-wavelength properties of a wide range of astrophysical systems from planetary disks to large-scale structures. To demonstrate the capability of the new ART$^2$, we applied it to two hydrodynamics simulations: the zoom-in Milky Way Simulation to obtain panchromatic properties of individual galaxies, and the large-scale IllustrisTNG100 Simulation to obtain global properties such as the line intensity mappings. These products are essential for a broad array of studies such as the correlations between physical and panchromatic properties and their evolution. By enabling direct comparison between numerical simulations and multi-band observations, ART$^2$ provides a crucial theoretical framework for the interpretations of existing observations, the plan for future surveys, and the synergy between multi-band galaxy surveys and line intensity mappings. Therefore, ART$^2$ is a powerful and versatile tool to bridge the gap between theories and observations of cosmic structures., Comment: Accepted for publication in MNRAS; 20 pages, 26 figures

The galaxy Malin 1 contains the largest stellar disk known but the formation mechanism of this structure has been elusive. In this paper, we report a Malin 1 analogue in the 100 Mpc IllustrisTNG simulation and describe its formation history. At redshift zero, this massive galaxy, having a maximum circular velocity $V_{\rm max}$ of 430 ${\rm km\ s^{-1}}$, contains a 100 kpc gas/stellar disk with morphology similar to Malin 1. The simulated galaxy reproduces well many observed features of Malin 1's vast disk, including its stellar ages, metallicities, and gas rotation curve. We trace the extended disk back in time and find that a large fraction of the cold gas at redshift zero originated from the cooling of hot halo gas, triggered by the merger of a pair of intruding galaxies. Our finding provides a novel way to form large galaxy disks as extreme as Malin 1 within the current galaxy formation framework., 5 page, 5 figures; resubmitted to MNRAS Letters after first referee report; Comments welcome. Animations of gas/stars can be found here at https://youtu.be/Ibl4Cyybw2Q and https://youtu.be/3aIpCu6e9dQ, or downloaded at http://www.tng-project.org/movies/tng/TNG_Malin_1_gas.mpeg and http://www.tng-project.org/movies/tng/TNG_Malin_1_star.mpeg

The impacts of the influent type in wastewater treatment plants (WWTPs) on the distribution patterns of the microbial community and functional characteristics were investigated. The obtained results indicated that the influent types exhibited evident influences on the microbial distribution patterns. The diversity and richness of functional microbes in HI-WWTP (with a ratio of >30% industrial wastewater in influents) were evidently decreased compared with those in HM- (with 70–90% municipal wastewater in influents) and M-WWTPs (with >90% municipal wastewater in influents). The core functional bacteria included denitrifiers, anaerobic fermentation bacteria (AFB), organic degrading bacteria (ODB), phosphorus accumulating organisms (PAO) and nitrite oxidizing bacteria (NOB), but they exhibited distinct abundances in WWTPs receiving different categories of wastewater. The denitrifiers in HI-WWTPs was 15.6–32.5% higher than that in other WWTPs, while PAOs had higher abundances in M − and HI-WWTPs (28.9% and 39.3%, respectively) compared with HM-WWTPs. Clear co-occurrence relationships were found among the main functional microbes with similar metabolic characteristics. Moreover, information on functional genes related to carbon, nitrogen and phosphorus metabolism, which is closely associated with pollutant removal efficiency, was obtained. M-WWTPs had higher abundances of genetic expressions for organic matters degradation (i.e. amino acid (10.42%) and carbohydrate (9.86%) metabolisms). Nar, Nir and Nor showed lowest abundances in HM-WWTPs, causing the low nitrogen removal (63.04–65.79%). However, influent type had little effect on genetic expression related with phosphorus removal. This work provided new insights into the interrelationship among bacterial co-occurrence, microbial activity and pollutant removal in WWTPs with different influent types.

It is established that electron transmission through chiral molecules depends on the electron's spin. This phenomenon, termed the chiral‐induced spin selectivity (CISS), effect has been observed in chiral molecules, supramolecular structures, polymers, and metal‐organic films. Which spin is preferred in the transmission depends on the handedness of the system and the tunneling direction of the electrons. Molecular motors based on overcrowded alkenes show multiple inversions of helical chirality under light irradiation and thermal relaxation. The authors found here multistate switching of spin selectivity in electron transfer through first generation molecular motors based on the four accessible distinct helical configurations, measured by magnetic‐conductive atomic force microscopy. It is shown that the helical state dictates the molecular organization on the surface. The efficient spin polarization observed in the photostationary state of the right‐handed motor coupled with the modulation of spin selectivity through the controlled sequence of helical states, opens opportunities to tune spin selectivity on‐demand with high spatio‐temporal precision. An energetic analysis correlates the spin injection barrier with the extent of spin polarization., The efficiency of electrons transport through chiral systems depends on their spin. Hence, chiral molecules are spin filters. Controlling the molecules' chirality provides a way to define the spin polarization. This molecular machine performs unidirectional rotations, inverting handedness of the molecule and therefore the spin‐polarization at each stage of the rotary cycle.

Direct $N$-body simulations of star clusters are accurate but expensive, largely due to the numerous $\mathcal{O} (N^2)$ pairwise force calculations. To solve the post-million-body problem, it will be necessary to use approximate force solvers, such as tree codes. In this work, we adapt a tree-based, optimized Fast Multipole Method (FMM) to the collisional $N$-body problem. The use of a rotation-accelerated translation operator and an error-controlled cell opening criterion leads to a code that can be tuned to arbitrary accuracy. We demonstrate that our code, Taichi, can be as accurate as direct summation when $N> 10^4$. This opens up the possibility of performing large-$N$, star-by-star simulations of massive stellar clusters, and would permit large parameter space studies that would require years with the current generation of direct summation codes. Using a series of tests and idealized models, we show that Taichi can accurately model collisional effects, such as dynamical friction and the core-collapse time of idealized clusters, producing results in strong agreement with benchmarks from other collisional codes such as NBODY6++GPU or PeTar. Parallelized using OpenMP and AVX, Taichi is demonstrated to be more efficient than other CPU-based direct $N$-body codes for simulating large systems. With future improvements to the handling of close encounters and binary evolution, we clearly demonstrate the potential of an optimized FMM for the modeling of collisional stellar systems, opening the door to accurate simulations of massive globular clusters, super star clusters, and even galactic nuclei., Published in ApJ. This is the updated version of the paper after revisions. Updated title

We present an N-body code called Taichi for galactic dynamics and controlled numerical experiments. The code includes two high-order hierarchical multipole expansion methods: the Barnes-Hut (BH) tree and the fast multipole method (FMM). For the time integration, the code can use either a conventional adaptive KDK or a Hamiltonian splitting integrator. The combination of FMM and the Hamiltonian splitting integrator leads to a momentum-conserving N-body scheme with individual time steps. We find Taichi performs well in the typical applications in galactic dynamics. In the isolated and interacting galaxies tests, the momentum conserving scheme produces the same result as a conventional BH tree code. But for similar force accuracies, FMM significantly speeds up the simulations compared to the monopole BH tree. In the cold collapse test, we find the inner structure after relaxation can be sensitive to the force accuracies. Taichi is ready to incorporate special treatment of close encounters thanks to the Hamiltonian splitting integrator, suitable for studying dynamics around central massive bodies.

This paper discusses the problems associated with the use of Fiber Bragg Grating (FBG) sensors to detect internal damage to composite specimens under low frequency cycling. This work utilized FBG sensor embedded cantilever beam specimens with and without known damage. FBG sensor measurement parameters which can reflect the location and degree of damage were obtained. Finally, the results obtained from the FBG sensors were compared to theoretical strain deviations, as calculated using ANSYS, to confirm the feasibility and range of sensitivity of FBG sensors for damage monitoring of composite material specimens. The research shows that FBG sensors can be used in detecting damage in composite materials under low frequency cycling and when the FBG senor is within 15 mm of the extent of the damage is over 2 mm.

In this work, a facile and effective approach was developed to enhance para-aramid fiber (AF). Poly-p-paraphenylene terephthalamide oligomer modified amino-functionalized multiwalled carbon nanotubes (PPTA-MWNTs-x) were prepared and deposited on the surface of AF. TEM and AFM analyses proved the successful grafting of PPTA oligomers onto the surface of MWNTs-NH2. The modified MWNTs showed better dispersion stability compared with that of MWNTs-NH2. PPTA-MWNTs-x deposited on the AF surface was characterized by SEM and XRD. SEM images showed a relatively homogeneous distribution of PPTA-MWNTs-x over the aramid fibers. XRD analysis showed the crystallographic index value of AF/PPTA-MWNTs-x increased significantly as compared to that of AF, suggesting a more regular and ordered crystalline structure. The tensile test and single fiber pullout test were conducted. The results confirmed that PPTA-MWNTs-x could greatly enhance the mechanical properties of AF and improve the interfacial properties of EP/AF and PP/AF composites.

Single-nucleotide polymorphisms in the human leukocyte antigen (HLA)-DQB1 gene are associated with chronic inflammatory and immunological diseases. Host genetic factors have a key role in the development of chronic hepatitis B (CHB). The aim of the present study was to inves- tigate the association between the HLA-DQB1 polymorphisms and the susceptibility to CHB. PubMed, Embase, CNKI and Wanfang databases were searched for the studies that reported the association of the HLA-DQB1 polymorphisms with CHB between January 1, 1966 and July 30, 2015. HLA-DQB1 polymorphism-specific odds ratio (OR) and 95% confidence intervals (95% CI) were pooled and calculated in the fixed effects model using the Mantel-Haenszel method. Q-test and I 2 test were performed to examine the heterogeneity. Begg's funnel test and Egger's test were conducted to assess publica- tion bias. All the statistical tests were two-tailed. Subsequent to searching the databases and screening according to the inclu- sion criteria, 7 case-control studies were available in the present meta-analysis, including 815 CHB patients and 731 control subjects for the HLA-DQB1 polymorphisms. In conclusion, the statistically significant pooled OR of the HLA-DQB1 polymorphisms were obtained for the HLA-DQB1 loci ( * 0201, case vs. control: I 2 =36.5%; P-value of heterogeneity=0.15; OR, 1.29; 95% CI, 1.02-1.64; P=0.0301; * 0301, case vs. control: I 2 =0%; P-value of heterogeneity=0.899; OR, 1.37; 95% CI, 1.12-1.69; P=0.002; * 0502, case vs. control: I 2 =24.9%; P-value of heterogeneity=0.239; OR, 1.50; 95% CI, 1.02-2.20; P=0.04), which were associated with an increased risk of CHB. Similar significant results were observed and acquired in the following HLA-DQB1 loci ( * 0303, case vs. control: I 2 =0%; P-value of heterogeneity=0.986; OR, 0.77; 95% CI, 0.62-0.95; P=0.017; * 0604, case vs. control: I 2 =0%; P-value of heterogeneity=0.594; OR, 0.38; 95% CI, 0.20-0.74; P=0.003), which were associated with a decreased risk of CHB. No significant association was observed for the other HLA-DQB1 family loci. The present meta-analysis demonstrated that the HLA-DQB1 loci ( * 0201, * 0301 and * 0502) polymorphisms were significantly associ - ated with an increased risk of CHB. However, HLA-DQB1 loci polymorphisms ( * 0303 and * 0604) were associated with a decreased risk of CHB. These results support the hypothesis that polymorphisms of the HLA-DQB1 allele families may affect the susceptibility or resistance to CHB.

By using the input-output model and the data of China’s industrial segment industries, this paper measure the wastewater emission reduction intensity and the wastewater emission reduction of China’s industrial imports in 2012 and 2015. At the same time, it also uses the LMDI to analyze the impact of the imports changes in scale, the structural and the intensity of the wastewater emission reduction by the imports on China’s industrial wastewater emission. The results are as follows:(1) In 2012 and 2015, China’s industrial product import caused its industrial wastewater discharge to decrease by 15% and 14% respectively; (2) The decreases in the scale of the imports and the intensity of wastewater emission reduction lowered the reduction of the emission but the change in the structure of the imports improved the capacity of the reduction.

The guidelines addressed the evidence-based indications for the management of children with acute infectious diarrhea in Chinese pediatric population. The experts group of evidence development put forward clinical problems, collects evidence, forms preliminary recommendations, and then uses open-ended discussions to form recommendations. The literature review was done for developing this guideline in databases including PubMed, Cochrane, EMBASE, China Biomedical Database, and Chinese Journal Full-text Database up to June 2013. Search the topic “acute diarrhea” or “enteritis” and “adolescent” or “child” or “Pediatric patient” or “Baby” or “Infant”. For the treatment of mild, moderate dehydration, hypotonic oral rehydration solutions (ORS) are strongly recommended. Intravenous (IV) rehydration is recommended for severe dehydration, with a mixture of alkali-containing dextrose sodium solution. Nasogastric feeding tube rehydration is used for children with severe dehydration without IV infusion conditions with ORS solution. Regular feeding should resume as soon as possible after oral rehydration or IV rehydration. The lactose-free diet can shorten the diarrhea duration. Zinc supplements are recommended in children with acute infectious diarrhea. Saccharomyces boulardii and Lactobacillus Rhamnus are recommended to be used in acute watery diarrhea. Saccharomyces boulardii is recommended in children with antibiotic-associated diarrhea as well. Montmorillonite and Racecadotril (acetorphan) can improve the symptoms of diarrhea or shorten the course of acute watery diarrhea. Antibiotics are recommended with dysenteric-like diarrhea, suspected cholera with severe dehydration, immunodeficiency, and premature delivery children with chronic underlying disease; otherwise, antibiotics are not recommended. The principles of the most controversial treatments with of acute infectious disease are reaching to a consensus in China.

We implement and test the exact time integration method proposed by Townsend 2009 for gas cooling in cosmological hydrodynamic simulations. The errors using this time integrator for the internal energy are limited by the resolution of the cooling tables and are insensitive to the size of the timestep, improving accuracy relative to explicit or implicit schemes when the cooling time is short. We compare results with different time integrators for gas cooling in cosmological hydrodynamic simulations. We find that the temperature of the gas in filaments before accreting into dark matter halos to form stars, obtained with the exact cooling integration, lies close to the equilibrium where radiative cooling balances heating from the UV background. For comparison, the gas temperature without the exact integrator shows substantial deviations from the equilibrium relation. Galaxy stellar masses with the exact cooling technique agree reasonably well, but are systematically lower than the results obtained by the other integration schemes, reducing the need for feedback to suppress star formation. Our implementation of the exact cooling technique is provided and can be easily incorporated into any hydrodynamic code., 9 pages, 6 figures, accepted

We present the results of cosmological hydrodynamic simulations with zoom-in initial conditions, and investigate the formation of the first galaxies and their evolution towards observable galaxies at $z \sim 6$. We focus on three different galaxies which end up in halos with masses $M_{h} = 2.4 \times10^{10}~h^{-1}\; M_{\odot}$ (Halo-10), $1.6 \times10^{11}~h^{-1}\; M_{\odot}$ (Halo-11) and $0.7 \times10^{12}~h^{-1} M_{\odot}$ (Halo-12) at z=6. Our simulations also probe impacts of different sub-grid assumptions, i.e., SF efficiency and cosmic reionization, on SF histories in the first galaxies. We find that star formation occurs intermittently due to supernova (SN) feedback at z > 10, and then it proceeds more smoothly as the halo mass grows at lower redshifts. Galactic disks are destroyed due to SN feedback, while galaxies in simulations with no-feedback or lower SF efficiency models can sustain galactic disk for long periods > 10 Myr. The expulsion of gas at the galactic center also affects the inner dark matter density profile. However, SN feedback does not seem to keep the shallow profile of dark matter for a long period. Our simulated galaxies in Halo-11 and Halo-12 reproduce the star formation rates (SFR) and stellar masses of observed Lyman-$��$ emitters (LAEs) at z = 7-8 fairly well given observational uncertainties. In addition, we investigate the effect of UV background radiation on star formation as an external feedback source, and find that earlier reionization extends the quenching time of star formation due to photo-ionization heating, but does not affect the stellar mass at z=6., 14 pages, 13 figures, submitted to ApJ

We study the orbital properties of dark matter haloes by combining a spectral method and cosmological simulations of Milky Way-sized galaxies. We compare the dynamics and orbits of individual dark matter particles from both hydrodynamic and $N$-body simulations, and find that the fraction of box, tube and resonant orbits of the dark matter halo decreases significantly due to the effects of baryons. In particular, the central region of the dark matter halo in the hydrodynamic simulation is dominated by regular, short-axis tube orbits, in contrast to the chaotic, box and thin orbits dominant in the $N$-body run. This leads to a more spherical dark matter halo in the hydrodynamic run compared to a prolate one as commonly seen in the $N$-body simulations. Furthermore, by using a kernel based density estimator, we compare the coarse-grained phase-space densities of dark matter haloes in both simulations and find that it is lower by $\sim0.5$ dex in the hydrodynamic run due to changes in the angular momentum distribution, which indicates that the baryonic process that affects the dark matter is irreversible. Our results imply that baryons play an important role in determining the shape, kinematics and phase-space density of dark matter haloes in galaxies., 12 pages, 9 figures

The "Disk of satellites" (DoS) around Milky Way is a highly debated topic with conflicting interpretations of observations and their theoretical models. We perform a comprehensive analysis of all dwarfs detected in the Milky Way and find that the DoS structure depends strongly on the plane identification method and the sample size. In particular, we demonstrate that a smaller sample size produces a higher anisotropy of the spatial distribution and a stronger clustering of the angular momentum of the satellites. Moreover, we calculate the evolution of the 11 classical satellites with proper motion measurements and find that the thin DoS they currently reside in is transient. Furthermore, we analyze two cosmological simulations using the same initial conditions of a Milky Way-sized galaxy, an N-body run with dark matter only and a hydrodynamic one with both baryonic and dark matter, and find that the hydrodynamic simulation produces more anisotropic distribution of satellites than the N-body one. Our results suggest that an anisotropic distribution of satellites in galaxies can originate from baryonic processes in the hierarchical structure formation model, but the claimed highly-flattened, coherently-rotating DoS of the Milky Way may be a small-number selection effect. These findings may help resolve the contradictory claims of DoS in other galaxies and the discrepancy among numerical simulations., Comment: Published in ApJ. 7 pages, 5 figures

The ground-breaking detections of gravitational waves from black hole mergers by LIGO have rekindled interest in primordial black holes (PBHs) and the possibility of dark matter being composed of PBHs. It has been suggested that PBHs of tens of solar masses could serve as dark matter candidates. Recent analytical studies demonstrated that compact ultra-faint dwarf galaxies can serve as a sensitive test for the PBH dark matter hypothesis, since stars in such a halo-dominated system would be heated by the more massive PBHs, their present-day distribution can provide strong constraints on PBH mass. In this study, we further explore this scenario with more detailed calculations, using a combination of dynamical simulations and Bayesian inference methods. The joint evolution of stars and PBH dark matter is followed with a Fokker-Planck code PhaseFlow. We run a large suite of such simulations for different dark matter parameters, then use a Markov Chain Monte Carlo approach to constrain the PBH properties with observations of ultra-faint galaxies. We find that two-body relaxation between the stars and PBH drives up the stellar core size, and increases the central stellar velocity dispersion. Using the observed half-light radius and velocity dispersion of stars in the compact ultra-faint dwarf galaxies as joint constraints, we infer that these dwarfs may have a cored dark matter halo with the central density in the range of 1-2 $\rm{M_{\odot}/pc^3}$, and that the PBHs may have a mass range of 2-14 $\rm{M_{\odot}}$ if they constitute all or a substantial fraction of the dark matter., Comment: 11 page, 6 figures, submitted to MNRAS; comments welcome

A large number of high-redshift galaxies have been discovered via their narrow-band Lyα line or broad-band continuum colours in recent years. The nature of the escaping process of photons from these early galaxies is crucial to understand galaxy evolution and the cosmic reionization. Here, we investigate the escape of Lyα, non-ionizing UV-continuum (λ = 1300-1600 A in rest frame), and ionizing photons (λ < 912 A) from galaxies by combining a cosmological hydrodynamic simulation with three-dimensional multiwavelength radiative transfer calculations. The galaxies are simulated in a box of 5^3 h^−3 Mpc^3 with high resolutions using the Aquila initial condition which reproduces a Milky Way-like galaxy at redshift z = 0. We find that the escape fraction (f_esc) of these different photons shows a complex dependence on redshift and galaxy properties: $f_{\rm esc}^{\rm \rm {Ly{\alpha }}}$ and $f_{\rm esc}^{\rm UV}$ appear to evolve with redshift, and they show similar, weak correlations with galaxy properties such as mass, star formation, metallicity, and dust content, while $f_{\rm esc}^{\rm Ion}$ remains roughly constant at ∼0.2 from z ∼ 0 to 10, and it does not show clear dependence on galaxy properties. $f_{\rm esc}^{\rm \rm {Ly{\alpha }}}$ correlates more strongly with $f_{\rm esc}^{\rm UV}$ than with $f_{\rm esc}^{\rm Ion}$. In addition, we find a relation between the emergent Lyα luminosity and the ionizing photon emissivity of Lyman Alpha Emitters (LAEs). By combining this relation with the observed luminosity functions of LAEs at different redshift, we estimate the contribution from LAEs to the reionization of intergalactic medium (IGM). Our result suggests that ionizing photons from LAEs alone are not sufficient to ionize IGM at z ≳ 6, but they can maintain the ionization of IGM at z ∼ 0–5.

To understand the epidemiological profiles of hand, foot and mouth disease (HFMD) and the major enteroviruses causing the epidemics of HFMD in Shanghai from 2010 to 2014.The city-wide surveillance data between 2010 and 2014 were used to analyze the epidemiologic characteristics of the HFMD outbreaks in Shanghai. The annual incidence of HFMD was estimated based on the 2010 Shanghai Census data.From 2010 to 2014, the reported HFMD cases were 41 080, 37 323, 51 172, 42 198, and 65 018, respectively; the severe cases (case-severity ratio) were 469 (1.14%), 456 (1.22%), 318 (0.62%), 104 (0.25%) and 248 (0.38%), respectively. Based on Shanghai census data by the end of 2010, the attack rates of HFMD in Shanghai were 0.16%-0.28% in the entire population. In terms of the proportion of HFMD cases and severe cases in the specific population, male accounted for 59.62%-61.48% and 62.26%-73.08%, migrant population accounted for 51.86%-62.40% and 72.01%-80.38%; children aged 1.0-1.9 years comprised the highest proportion, up to 22.70%-27.00% and 32.08%-36.40%. HFMD peaked from April to July, in parallel with the peak circulation of enterovirus (EV) 71, and a small peak usually occurred in autumn and winter. All the critically severe and fatal cases were caused by EV71. The detection rates of EV71 and Coxsackievirus A (CA) 16 were 73.08%-88.09% and 1.12%-2.90% in severe HFMD cases, 19.75%-48.74% and 2.02%-23.69% in uncomplicated inpatients, and 16.78%-40.08% and 8.36%-33.39% in mild community cases, respectively. The detection rates of CA6 and CA10 in the mild community cases in 2014 were 18.38% and 1.43%, respectively. In 2013 non-EV71 and non-CA16 enteroviruses comprised 74.86% in the community cases.The annual HFMD outbreaks occurred in Shanghai during 2010-2014. Children under 5 years of age, migrant population and male were the major susceptible population. EV71 and CA16 were the predominant pathogens causing the epidemics of HFMD except in 2013, and CA6 was prevalent in the community cases in 2014. The major peak season of HFMD usually overlapped with the peak of EV71 circulation and the majority of severe HFMD cases were associated with EV71 infection.

Observations of globular clusters show that they have universal lognormal mass functions with a characteristic peak at $\sim 2\times 10^{5}\, {\rm{M_{\odot}}}$, but the origin of this peaked distribution is highly debated. Here we investigate the formation and evolution of star clusters in interacting galaxies using high-resolution hydrodynamical simulations performed with two different codes in order to mitigate numerical artifacts. We find that massive star clusters in the range of $\sim 10^{5.5} - 10^{7.5}\, {\rm{M_{\odot}}}$ form preferentially in the highly-shocked regions produced by galaxy interactions. The nascent cluster-forming clouds have high gas pressures in the range of $P/k \sim 10^8 - 10^{12}\, \rm{K}\,\rm{cm^{-3}}$, which is $\sim 10^4 - 10^8$ times higher than the typical pressure of the interstellar medium but consistent with recent observations of a pre-super star cluster cloud in the Antennae Galaxies. Furthermore, these massive star clusters have quasi-lognormal initial mass functions with a peak around $\sim 10^{6}\, {\rm{M_{\odot}}}$. The number of clusters declines with time due to destructive processes, but the shape and the peak of the mass functions do not change significantly during the course of galaxy collisions. Our results suggest that gas-rich galaxy mergers may provide a favorable environment for the formation of massive star clusters such as globular clusters, and that the lognormal mass functions and the unique peak may originate from the extreme high-pressure conditions of the birth clouds and may survive the dynamical evolution., Comment: Accepted in ApJ. 16 pages, 9 figures