Abstract
The nature of the rare “Changing-look” (CL) phenomenon in active galactic nuclei (AGNs) is still under debate. We present Swift/XRT and UVOT follow-up observations of UGC 3223, a newly ...discovered repeat CL-AGN with type transitions of S1.5 → S2 → S1.8 occurring in a period of about 30 yr. By comparing the values previously reported in the ROSAT All-sky Survey and in the second Swift-XRT Point Source catalog, we clearly find that the X-ray flux tightly follows the optical spectral transition, in which a spectral type closer to a Seyfert 1 type is associated with a higher X-ray flux. An invariable X-ray spectral shape is, however, found in the CL phenomenon of the object. An extremely low Eddington ratio of ∼2 × 10
−4
can be obtained from the X-ray luminosity for its Seyfert 2 state, which suggests the disk-wind broad-line region model best explains the CL phenomenon. A variation of the total UV emission is not revealed when compared to the previous Galaxy Evolution Explorer NUV observation, since the UVOT images indicate that ∼90% UV emission comes from intensive star formation in the host galaxy.
Summary
Previous studies have focused on the relationship between hepatitis B virus (HBV) infection and non‐Hodgkin lymphoma (NHL). However, the results remain inconsistent and somehow conflicting in ...different subgroups. The aim of this study was to combine the findings of independent studies to comprehensively assess the association between HBV and NHL using a meta‐analysis. Relevant studies were identified through structured keyword searches in PubMed, EMBASE and the China National Knowledge Infrastructure (CNKI) database, and 58 studies with a total of 53 714 NHL cases and 1 778 591 controls were finally included. Pooled estimates indicated a significantly increased NHL risk in HBV‐infected individuals (summary odds ratio sOR: 2.50; 95% confidence interval CI: 2.20‐2.83) regardless of the study design (case–control studies: sOR: 2.47; 95% CI: 2.16‐2.82; cohort studies: sOR: 2.64; 95% CI: 1.78‐3.91). Considerable heterogeneity was observed across studies that was primarily attributed to the NHL subtypes (meta‐regression: P < .05). Overall, B‐cell NHL (sOR: 2.46; 95% CI: 1.97‐3.07) presented a stronger association with HBV infection than T‐cell NHL (sOR: 1.67; 95% CI: 1.34‐2.10). Within the B‐cell NHL subtypes, HBV infection was significantly associated with diffuse large B‐cell lymphoma (DLBCL, sOR: 2.06; 95% CI: 1.48‐2.88) and follicular lymphoma (FL, sOR: 1.54; 95% CI: 1.11‐2.12), but not with chronic lymphocytic leukaemia/small lymphocytic lymphoma (CLL/SLL) and Burkitt lymphoma. The results of this meta‐analysis support a positive link between HBV infection and NHL development. Further investigations for the mechanisms underlying HBV‐induced NHL are warranted.
Lung cancer is the most common cancer in China. Previous studies have indicated that lung cancer incidence exhibits remarkable spatial heterogeneity, and lung cancer is related to outdoor air ...pollution. However, the non-linear spatial association between outdoor air pollution and lung cancer incidence in China remains unclear.
In this study, the relationships between the lung cancer incidence of males and females from 207 counties in China in 2013 with annual concentrations of PM2.5, PM10, SO
, NO
, CO and O
were analysed. GeoDetector q statistic was used for examining the non-linear spatial association between outdoor air pollution and incidence of lung cancer.
An apparent spatial and population gender heterogeneity was found in the spatial association between outdoor air pollution and lung cancer incidence. Among the six selected pollutants, SO
has the greatest influence on lung cancer (q = 0.154 in females) in north China. In the south, each selected pollutant has a significant impact on males or females, and the mean q value in the south is 0.181, which is bigger than that in the north (q = 0.154). In addition, the pollutants have evident non-linear interaction effects on lung cancer. In north China, the interaction between SO
and PM2.5 is the dominant interaction, with q values of 0.207 in males and 0.334 in females. In the south, the dominant interactive factors are between SO
and O
in males and between SO
and CO in females, with q values of 0.45, 0.232 respectively. Smoking is a substantial contributor to lung cancer among men, either in South or North China, with q value of 0.143 and 0.129 respectively, and the interaction between smoking and air pollutants increases this risk.
This study implies that the influence of SO
and PM2.5 on lung cancer should be focused on in north China, and in the south, the impact of O
and CO as well as their interaction with SO
need to be paid more attention. Smoking, particularly in men, remains a significant risk factor for lung cancer in both North and South China.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Directional couplers are extensively used devices in integrated optics, but suffer from limited operational wavelength range. Here we use, for the first time, the dispersive properties of ...sub-wavelength gratings to achieve a fivefold enhancement in the operation bandwidth of a silicon-on-insulator directional coupler. This approach does not compromise the size or the phase response of the device. The sub-wavelength grating based directional coupler we propose covers a 100 nm bandwidth with an imbalance of ≤ 0.6 dB between its outputs, as supported by full 3D FDTD simulations.
Chromosome 17q21-ter is commonly gained in neuroblastoma, but it is unclear which gene in the region is important for tumorigenesis. The JMJD6 gene at 17q21-ter activates gene transcription. Here we ...show that JMJD6 forms protein complexes with N-Myc and BRD4, and is important for E2F2, N-Myc and c-Myc transcription. Knocking down JMJD6 reduces neuroblastoma cell proliferation and survival in vitro and tumor progression in mice, and high levels of JMJD6 expression in human neuroblastoma tissues independently predict poor patient prognosis. In addition, JMJD6 gene is associated with transcriptional super-enhancers. Combination therapy with the CDK7/super-enhancer inhibitor THZ1 and the histone deacetylase inhibitor panobinostat synergistically reduces JMJD6, E2F2, N-Myc, c-Myc expression, induces apoptosis in vitro and leads to neuroblastoma tumor regression in mice, which are significantly reversed by forced JMJD6 over-expression. Our findings therefore identify JMJD6 as a neuroblastoma tumorigenesis factor, and the combination therapy as a treatment strategy.
We use the high-resolution Aquarius simulations of the formation of Milky Way-sized haloes in the Λ cold dark matter cosmology to study the effects of dark matter substructures on gravitational ...lensing. Each halo is resolved with ∼108 particles (at a mass resolution mp∼ 103 to 104 h−1 M⊙) within its virial radius. Subhaloes with masses msub≳ 105 h−1 M⊙ are well resolved, an improvement of at least two orders of magnitude over previous lensing studies. We incorporate a baryonic component modelled as a Hernquist profile and account for the response of the dark matter via adiabatic contraction. We focus on the ‘anomalous’ flux ratio problem, in particular on the violation of the cusp–caustic relation due to substructures. We find that subhaloes with masses less than ∼108 h−1 M⊙ play an important role in causing flux anomalies; such low-mass subhaloes have been unresolved in previous studies. There is large scatter in the predicted flux ratios between different haloes and between different projections of the same halo. In some cases, the frequency of predicted anomalous flux ratios is comparable to that observed for the radio lenses, although in most cases it is not. The probability for the simulations to reproduce the observed violations of the cusp lenses is ≈10−3. We therefore conclude that the amount of substructure in the central regions of the Aquarius haloes is insufficient to explain the observed frequency of violations of the cusp–caustic relation. These conclusions are based purely on our dark matter simulations which ignore the effect of baryons on subhalo survivability.
Check dams are commonly used for soil conservation. In the Loess Plateau of China, check dams have been widely constructed as the principal means to retain floodwater and intercept soil sediments ...since the 1970s. For instance, there are more than 6572 check dams in the Yanhe watershed with an area of 7725 km2 in the Loess Plateau. However, little research has been done to quantify the hydrological effects of the check dams. In this research, the SWAT model (Soil and Water Assessment Tool) was applied to simulate the runoff and sediment in the Yanhe watershed. We treated the 1950s to 1960s as the reference period since there were very few check dams during the period. The model was firstly calibrated and validated in the reference period. The calibrated model was then used in the later periods to simulate the hydrological effects of the check dams. The results showed that the check dams had a regulation effect on runoff and a retention effect on sediment. From 1984 to 1987, the runoff in rainy season (from May to October) decreased by 1.54 m3 s−1 (14.7%) to 3.13 m3 s−1 (25.9%) due to the check dams; while in dry season (from November to the following April), runoff increased by 1.46 m3 s−1 (60.5%) to 1.95 m3 s−1 (101.2%); the sediment in rainy season decreased by 2.49 × 106 ton (34.6%) to 4.35 × 106 ton (48.0%). From 2006 to 2008, the runoff in rainy season decreased by 0.79 m3 s−1 (15.5%) to 1.75 m3 s−1 (28.9%), and the runoff in dry season increased by 0.51 m3 s−1 (20.1%) to 0.97 m3 s−1 (46.4%); the sediment in rainy season decreased by 2.03 × 106 ton (79.4%) to 3.12 × 106 ton (85.5%). Construction of the large number of check dams in the Loess Plateau has enhanced the region's capacity to control the runoff and sediment. In the Yanhe watershed, the annual runoff was reduced by less than 14.3% due to the check dams; and the sediment in rainy season was blocked by up to 85.5%. Thus, check dams are effective measures for soil erosion control in the Loess Plateau.
For generations the study of vocal development and its role in language has been conducted laboriously, with human transcribers and analysts coding and taking measurements from small recorded ...samples. Our research illustrates a method to obtain measures of early speech development through automated analysis of massive quantities of day-long audio recordings collected naturalistically in children's homes. A primary goal is to provide insights into the development of infant control over infrastructural characteristics of speech through large-scale statistical analysis of strategically selected acoustic parameters. In pursuit of this goal we have discovered that the first automated approach we implemented is not only able to track children's development on acoustic parameters known to play key roles in speech, but also is able to differentiate vocalizations from typically developing children and children with autism or language delay. The method is totally automated, with no human intervention, allowing efficient sampling and analysis at unprecedented scales. The work shows the potential to fundamentally enhance research in vocal development and to add a fully objective measure to the battery used to detect speech-related disorders in early childhood. Thus, automated analysis should soon be able to contribute to screening and diagnosis procedures for early disorders, and more generally, the findings suggest fundamental methods for the study of language in natural environments.
PDF
