[Epidemiological analysis of 1494 cases of pneumoconiosis in a city]

Objective: To analyze the prevalence of pneumoconiosis in Yichang City from 2006 to 2016, and to provide a scientific basis for the administrative department to formulate prevention and control strategies for pneumoconiosis. Methods: From 2006 to 2016, through the China Disease Control Information System Occupational Disease and Occupational Health Inspection System, relevant data were obtained, and the types of pneumoconiosis, the disease area and the dust-collecting age in Yichang City were statistically analyzed. Results: There were 1494 cases of pneumoconiosis in Yichang City, which were mainly distributed in 1 076 cases (72.02%) of coal workers' pneumoconiosis and 382 cases (25.57%) of silicosis, which occurred in Yiling District, Changyang County, Yidu City and Zigui County. The average age of dust collection was 13.78 years, and the age of onset was mainly concentrated in 5~9 years (35.27%) and 10~19 years (30.32%) . The incidence and severity of pneumoconiosis (phase) were related to the age of dusting (P<0.01) . Conclusion: The pneumoconiosis in Yichang City is mainly concentrated in the mining industry. The types of pneumoconiosis are mainly coal workers' pneumoconiosis. The occupational health and health management of key industries, regions and types of work should be strengthened.

Effects of different diets on the intestinal microbiota and immunity of common carp (Cyprinus carpio)

AIMS

An 8-week trial was performed to evaluate the differences in the intestinal microbiota and immune function of common carp (Cyprinus carpio)-fed different diets.

METHODS AND RESULTS

The fish (initial weight 492·6 ± 30 g, n = 270) were randomly divided into three groups with three replicates and were fed earthworms (group A), earthworms + duckweed (group M) or duckweed (group P) respectively. The diversity and dominant microbiota of the intestinal bacteria were detected by denaturing gradient gel electrophoresis, and the abundance of dominant bacteria was quantified by qPCR. Additionally, the activities of some nonspecific immune enzymes and antioxidant enzymes were determined. The results showed that higher diversity and abundance of intestinal microbiota were observed in group M and group P (P < 0·05). Based on the intestinal microbiota, Cetobacterium was only detected in the intestines of common carp in group A, and Bacillus was identified in groups M and P. Additionally, a higher abundance of Bacteroidetes and Firmicutes was also found in the intestine in group P than in group A (P < 0·05). Interestingly, the higher activities of immune enzymes were detected in intestine of common carp in group M, such as acid phosphatase, phosphatase (AKP), lysozyme, total antioxidant capacity, superoxide dismutase, catalase, glutathione peroxidase. In addition, the lower level of metabolites were also detected, such as nitric oxide and malondialdehyde.

CONCLUSIONS

Our results indicate that the intestinal microbiota and intestinal immunity of common carp were affected by diet. Meanwhile, the results show that a mixed diet can promote and improve the immune function of the omnivorous carp intestine, which suggests that paddy fields might be more suitable for the intestinal health and animal welfare of omnivorous fishes because they contain plant and animal diets.

SIGNIFICANCE AND IMPACT OF THE STUDY

As an ecological aquaculture strategy, the rice-fish mode has attracted attention among farmers, researchers and even consumers, especially for the cultivation of common carp in paddy fields. In paddy fields, fish can eat plant- and animal-based diets. However, it is not clear whether common carp feeding on a mixed diet in paddy fields have better intestinal health. This experiment is one of only a few studies performed from the perspective of intestinal micro-organisms and immunity to successfully study the effects of different natural diets on adult common carp. This study also provides a theoretical basis for healthy breeding of common carp in paddy fields.

Tests of General Relativity with GW170817

The recent discovery by Advanced LIGO and Advanced Virgo of a gravitational wave signal from a binary neutron star inspiral has enabled tests of general relativity (GR) with this new type of source. This source, for the first time, permits tests of strong-field dynamics of compact binaries in the presence of matter. In this Letter, we place constraints on the dipole radiation and possible deviations from GR in the post-Newtonian coefficients that govern the inspiral regime. Bounds on modified dispersion of gravitational waves are obtained; in combination with information from the observed electromagnetic counterpart we can also constrain effects due to large extra dimensions. Finally, the polarization content of the gravitational wave signal is studied. The results of all tests performed here show good agreement with GR.

The study of cationic waterborne polyurethanes modified by two different forms of polydimethylsiloxane

Two kinds of dimethylpolysiloxane, KF-6001 and X-22-176-DX, were used to modify polyurethane. The effects of KF-6001 and X-22-176-DX on the colloidal, physico-chemical and surface properties were studied for polydimethylsiloxane modified cationic waterborne polyurethanes (SiCWPUs). The chemical structures and the surface morphologies of the SiCWPUs are characterized via Fourier transform infrared spectrometry and scanning electron microscopy. The results showed that the addition of siloxane changes the structure and surface morphology of the polyurethane. The element distributions in the polymer films were tested via X-ray photoelectron spectroscopy, and the effect of the hydrophobicity of the surfaces of the polymer films of the cationic waterborne polyurethanes was demonstrated via water contact angle tests on the surfaces of the films. As the amount of siloxane added increases, the silicon content on the surfaces of the SiCPWU1 films increases from 0% to 17.92%, and the actual silicon content on the surfaces of the films was much larger than the theoretical value. Therefore, the hydrophobicity of the membrane surface increases sharply, and the contact angle increases from 63.0° to 105.3°. Dynamic mechanical analysis indicates that the introduction of polydimethylsiloxane into the cationic aqueous polyurethane chain increases microphase separation in the polymer films. Stress–strain data showed that the mechanical properties of SiCPWU1 films were better than those of SiCPWU2 films when the same amounts of PDMS were added.

Two kinds of dimethylpolysiloxane, KF-6001 and X-22-176-DX, were used to modify polyurethane.

Constraining the p-Mode-g-Mode Tidal Instability with GW170817

We analyze the impact of a proposed tidal instability coupling p modes and g modes within neutron stars on GW170817. This nonresonant instability transfers energy from the orbit of the binary to internal modes of the stars, accelerating the gravitational-wave driven inspiral. We model the impact of this instability on the phasing of the gravitational wave signal using three parameters per star: an overall amplitude, a saturation frequency, and a spectral index. Incorporating these additional parameters, we compute the Bayes factor (lnB_{!pg}^{pg}) comparing our p-g model to a standard one. We find that the observed signal is consistent with waveform models that neglect p-g effects, with lnB_{!pg}^{pg}=0.03_{-0.58}^{+0.70} (maximum a posteriori and 90% credible region). By injecting simulated signals that do not include p-g effects and recovering them with the p-g model, we show that there is a ≃50% probability of obtaining similar lnB_{!pg}^{pg} even when p-g effects are absent. We find that the p-g amplitude for 1.4  M_{⊙} neutron stars is constrained to less than a few tenths of the theoretical maximum, with maxima a posteriori near one-tenth this maximum and p-g saturation frequency ∼70  Hz. This suggests that there are less than a few hundred excited modes, assuming they all saturate by wave breaking. For comparison, theoretical upper bounds suggest ≲10^{3} modes saturate by wave breaking. Thus, the measured constraints only rule out extreme values of the p-g parameters. They also imply that the instability dissipates ≲10^{51}  erg over the entire inspiral, i.e., less than a few percent of the energy radiated as gravitational waves.

Synthesis of a novel flame retardant based on DOPO derivatives and its application in waterborne polyurethane

An intumescent flame retardant (DOPO-DAM) containing phosphorus and nitrogen was synthesized via a two-step process and then, it was incorporated into waterborne polyurethane to serve as a reactive flame retardant for preparing flame-retarded WPU (FR-WPU). The chemical structures of DOPO-DAM and FR-WPU were confirmed by ¹H NMR, ³¹P NMR, and FTIR studies. The thermal stability, flame retardancy and mechanical properties of FR-WPU were investigated by TGA, TGA-FIR, Py-GC-MS, limiting oxygen index (LOI) test, SEM-EDS analysis, cone calorimeter test and a universal testing machine. The results showed that the conjugation of DOPO-DAM into WPU induced a slight decline in the thermal stability of FR-WPU. However, the incorporation of DOPO-DAM into WPU significantly enhanced the flame retardancy by reducing the heat release rate (HRR), total heat release (THR), smoke production rate (SPR) and total smoke production (TSP). In addition, the morphology, elemental composition and content of the residual char of the flame-retarded WPU indicated the important function of DOPO-DAM in the condensed phase. Thus, DOPO-DAM exhibited gas-phase and condensed-phase flame retardant effects on the WPU films.

An intumescent flame retardant (DOPO-DAM) containing phosphorus and nitrogen was synthesized via a two-step process and it was incorporated into waterborne polyurethane to serve as a reactive flame retardant for preparing flame-retarded WPU (FR-WPU).

Sustainable and tough polyurethane films with self-healability and flame retardance enabled by reversible chemistry and cyclotriphosphazene

Self-healable, flame-retardant, recyclable, and robust polyurethane films were enabled by thermally driven Diels–Alder chemistry and cyclotriphosphazene.

Acidity-triggered zwitterionic prodrug nano-carriers with AIE properties and amplification of oxidative stress for mitochondria-targeted cancer theranostics

A TPE-based polyurethane prodrug has been established for mitochondria-targeting drug delivery and real-time monitoring.

[Association between distribution of bacillary dysentery and meteorological factors in Beijing, 2004-2015]

Objective: To analyze the distribution characteristics of bacillary dysentery in Beijing during 2004-2015 and evaluate the influence of meteorological factors on the temporal and spatial distribution of bacillary dysentery. Methods: The incidence data of bacterial dysentery and meteorological data in Beijing from 2004 to 2015 were collected. Descriptive epidemiological analysis was conducted to study the distribution characteristics of bacterial dysentery. Linear correlation analysis and multiple linear regression analysis were carried out to investigate the relationship between the incidence of bacillary dysentery and average precipitation, average air temperature, sunshine hours, average wind speed, average air pressure, gale and rain days. Results: A total of 280 704 cases of bacterial dysentery, including 36 deaths, were reported from 2004 to 2015 in Beijing, the average annual incidence was 130.15/100 000. The annual incidence peak was mainly between May and October, the cases occurred during this period accounted for 80.75% of the total, and the incidence was highest in age group 0 year. The population distribution showed that most cases were children outside child care settings and students, and the sex ratio of the cases was 1.22∶1. The reported incidence of bacillary dysentery was positively associated with average precipitation, average air temperature and rain days with the correlation coefficients of 0.931, 0.878 and 0.888, but it was negatively associated with the average pressure, the correlation coefficient was -0.820. Multiple linear regression equation for fitting analysis of bacillary dysentery and meteorological factors was Y=3.792+0.162X(1). Conclusion: The reported incidence of bacillary dysentery in Beijing was much higher than national level. The annual incidence peak was during July to August, and the average precipitation was an important meteorological factor influencing the incidence of bacillary dysentery.

Search for Subsolar-Mass Ultracompact Binaries in Advanced LIGO's First Observing Run

We present the first Advanced LIGO and Advanced Virgo search for ultracompact binary systems with component masses between 0.2  M_{⊙}-1.0  M_{⊙} using data taken between September 12, 2015 and January 19, 2016. We find no viable gravitational wave candidates. Our null result constrains the coalescence rate of monochromatic (delta function) distributions of nonspinning (0.2  M_{⊙}, 0.2  M_{⊙}) ultracompact binaries to be less than 1.0×10^{6}  Gpc^{-3}  yr^{-1} and the coalescence rate of a similar distribution of (1.0  M_{⊙}, 1.0  M_{⊙}) ultracompact binaries to be less than 1.9×10^{4}  Gpc^{-3}  yr^{-1} (at 90% confidence). Neither black holes nor neutron stars are expected to form below ∼1  M_{⊙} through conventional stellar evolution, though it has been proposed that similarly low mass black holes could be formed primordially through density fluctuations in the early Universe and contribute to the dark matter density. The interpretation of our constraints in the primordial black hole dark matter paradigm is highly model dependent; however, under a particular primordial black hole binary formation scenario we constrain monochromatic primordial black hole populations of 0.2  M_{⊙} to be less than 33% of the total dark matter density and monochromatic populations of 1.0  M_{⊙} to be less than 5% of the dark matter density. The latter strengthens the presently placed bounds from microlensing surveys of massive compact halo objects (MACHOs) provided by the MACHO and EROS Collaborations.

GW170817: Measurements of Neutron Star Radii and Equation of State

On 17 August 2017, the LIGO and Virgo observatories made the first direct detection of gravitational waves from the coalescence of a neutron star binary system. The detection of this gravitational-wave signal, GW170817, offers a novel opportunity to directly probe the properties of matter at the extreme conditions found in the interior of these stars. The initial, minimal-assumption analysis of the LIGO and Virgo data placed constraints on the tidal effects of the coalescing bodies, which were then translated to constraints on neutron star radii. Here, we expand upon previous analyses by working under the hypothesis that both bodies were neutron stars that are described by the same equation of state and have spins within the range observed in Galactic binary neutron stars. Our analysis employs two methods: the use of equation-of-state-insensitive relations between various macroscopic properties of the neutron stars and the use of an efficient parametrization of the defining function p(ρ) of the equation of state itself. From the LIGO and Virgo data alone and the first method, we measure the two neutron star radii as R_{1}=10.8_{-1.7}^{+2.0}  km for the heavier star and R_{2}=10.7_{-1.5}^{+2.1}  km for the lighter star at the 90% credible level. If we additionally require that the equation of state supports neutron stars with masses larger than 1.97  M_{⊙} as required from electromagnetic observations and employ the equation-of-state parametrization, we further constrain R_{1}=11.9_{-1.4}^{+1.4}  km and R_{2}=11.9_{-1.4}^{+1.4}  km at the 90% credible level. Finally, we obtain constraints on p(ρ) at supranuclear densities, with pressure at twice nuclear saturation density measured at 3.5_{-1.7}^{+2.7}×10^{34}  dyn cm^{-2} at the 90% level.

PGK1 as an immune target in Kawasaki disease

Kawasaki disease (KD) is an immune-mediated vasculitis with symptoms that mimic febrile illness; the immune origin has been suggested but never proved. First, cell chip technology was used to screen immune targets cells. With the indirect immunofluorescence assay we found that the HeLa cell chip could be recognized by KD patient serum samples. The target cell proteome was extracted as antigens, and antigen recognition reaction was performed using the patients' serum as antibodies and the detected target protein was detected and identified as phosphoglycerate kinase 1 (PGK1). Then PGK1 was produced and tested with enzyme-linked immunosorbent assay (ELISA), Western blotting, immunoprecipitation and competitive inhibition immunofluorescence assay. Immunoglobulin (Ig)G against PGK1 was detected in 46% (23 of 50) sera of KD patients, 13% (five of 38) sera in febrile non-KD patients (FC) and 2·6% (one of 38) sera in healthy donors. As an immune target, PGK1 not only helps understanding of the pathogenesis, it also has potential value in facilitating the laboratory diagnosis of KD.

The mechanical principles behind the golden ratio distribution of veins in plant leaves

Tree leaves are commonly composed of thin mesophyll, carrying out photosynthesis under sunlight, and thick veins. Although the role of leaf veins in water transportation has been known for a long time, their role in providing structural support and guaranteeing large sunlighted area was rarely studied and remains elusive. Here, with use of a novel inverse optimization approach, we aim for uncovering the material design principle behind the unique pattern of venation. It is intriguing to observe that an almost Golden Ratio (GR) distribution of leaf veins always provides optimized structural behavior. Specifically, our research reveals, for the first time, that this unique GR distribution of relatively strong vein material is helpful for maximizing the bending stiffness and leading to a large sunlighted area which is vital for the photosynthesis process of a leaf. Moreover, the GR distribution of leaf veins is also observed in a wide class of plant leaf geometries (i.e., shape, thickness), where experimental evidence is provided for the optimized results. Therefore, our findings can not only serve to explain the mystery of veins GR distribution but also provide widely applicable guidelines on designing soft structures with exceptional mechanical performances.

Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω_{0}^{T}<5.58×10^{-8}, Ω_{0}^{V}<6.35×10^{-8}, and Ω_{0}^{S}<1.08×10^{-7} at a reference frequency f_{0}=25  Hz.

Behavioral and endocrine responses to season and social dynamics of captive male southern hairy-nosed wombats (Lasiorhinus latifrons)

Although southern hairy-nosed wombats (SHN wombats; Lasiorhinus latifrons) rarely breed in captivity, further knowledge of their reproductive physiology and behavior is likely to improve their breeding potential. This study examined the effect of seasonal variation and changes in social dynamics on the physiology and behavior of a captive population of male SHN wombats (n = 6). Seasonal changes in urinary testosterone metabolites (UTM), urinary cortisol metabolites (UCM), qualitative estimates of spermatorrhoea (QS), aggressive behavior and reproductive behavior were measured over an 11-month period. While there was no effect of month on QS (GLM ANOVA, P = 0.27), reproductive behavior (GLM ANOVA, P = 0.19) or aggressive behavior (Tukey pairwise comparisons), the secretion of UTM (GLM ANOVA, P = 0.051) was only marginally affected by season, compared to that reported for wild male SHN wombats. Mean UCM concentrations of July and August 2016 were significantly higher than those between October 2015 and January 2016 (Tukey pairwise comparisons). To examine social dynamics, two trials of animal positioning exchange with the enclosure system were implemented and behavioral data were examined for each trial over a six week period; UTM, UCM and general behaviors (n = 27) were measured for each trial. Neither UTM nor UCM concentration varied significantly (P ≥ 0.45) before and after the exchanges. "Scratching" decreased at the group level following the animal exchange in both trials, suggesting reduction in self-grooming may be a behavioral response to novel stimuli. UCM and UTM concentrations were both positively correlated with "standing still" and "body rub" behaviors. This may be evidence of a hormonal control of a "freezing behavioral response" to external stimuli and marking behavior, respectively. As there was no evidence that changing the social dynamics affected reproductive or agonistic behavior or hormone concentrations, it was concluded that captive male wombats in this study showed reduced reproductive seasonality compared to wild wombats and that animal exchange resulted in a behavioral response to novel stimuli but was not sufficient to affect testosterone or cortisol secretion, within the context of our study.

GW170817: Implications for the Stochastic Gravitational-Wave Background from Compact Binary Coalescences

The LIGO Scientific and Virgo Collaborations have announced the event GW170817, the first detection of gravitational waves from the coalescence of two neutron stars. The merger rate of binary neutron stars estimated from this event suggests that distant, unresolvable binary neutron stars create a significant astrophysical stochastic gravitational-wave background. The binary neutron star component will add to the contribution from binary black holes, increasing the amplitude of the total astrophysical background relative to previous expectations. In the Advanced LIGO-Virgo frequency band most sensitive to stochastic backgrounds (near 25 Hz), we predict a total astrophysical background with amplitude Ω_{GW}(f=25  Hz)=1.8_{-1.3}^{+2.7}×10^{-9} with 90% confidence, compared with Ω_{GW}(f=25  Hz)=1.1_{-0.7}^{+1.2}×10^{-9} from binary black holes alone. Assuming the most probable rate for compact binary mergers, we find that the total background may be detectable with a signal-to-noise-ratio of 3 after 40 months of total observation time, based on the expected timeline for Advanced LIGO and Virgo to reach their design sensitivity.