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"Cheng, S"
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Repeating fast radio burst 20201124A originates from a magnetar/Be star binary
Fast radio bursts (FRBs) are cosmic sources emitting millisecond-duration radio bursts. Although several hundreds FRBs have been discovered, their physical nature and central engine remain unclear. The variations of Faraday rotation measure and dispersion measure, due to local environment, are crucial clues to understanding their physical nature. The recent observations on the rotation measure of FRB 20201124A show a significant variation on a day time scale. Intriguingly, the oscillation of rotation measure supports that the local contribution can change sign, which indicates the magnetic field reversal along the line of sight. Here we present a physical model that explains observed characteristics of FRB 20201124A and proposes that repeating signal comes from a binary system containing a magnetar and a Be star with a decretion disk. When the magnetar approaches the periastron, the propagation of radio waves through the disk of the Be star naturally leads to the observed varying rotation measure, depolarization, large scattering timescale, and Faraday conversion. This study will prompt to search for FRB signals from Be/X-ray binaries.
Fast radio bursts (FRBs) are bright millisecond or shorter duration transient events. Here, the authors propose that FRB 20201124A comes from a binary system of a magnetar and a Be star with a decretion disk.
Journal Article
Sensory systems for robotic applications
Thanks to advances in sensing and computer vision technologies, robots can be found today in healthcare, medicine and the industry. Topics covered in this edited book include various types of sensors used in robotics, sensing schemes, sensing technologies and their applications including robotics, prosthetics, wearables and healthcare. Written for those working in robotics, sensor technologies and electronics, and their applications in robotics, haptics, prosthetics, wearable and interactive systems, cognitive engineering, neuro-engineering, computational neuroscience, medicine, and healthcare technologies.
BOOK
Recurrent Somatic DICER1 Mutations in Nonepithelial Ovarian Cancers
Primitive cancers have so-called hot-spot mutations in
DICER1
that alter the function of
DICER1,
an enzyme that processes microRNA. Some of these cancers harbor a loss-of-function mutation in the other
DICER1
allele, suggesting a new mutational mechanism of oncogenesis.
Sex cord–stromal tumors and germ-cell tumors account for less than 10% of ovarian cancers.
1
Unlike epithelial ovarian cancers, both sex cord–stromal tumors and germ-cell tumors can also occur in the testicle; testicular germ-cell tumors are the most common cancer in boys and men of European descent between the ages of 15 and 34 years.
2
,
3
Other than a pathognomonic somatic mutation in
FOXL2
in adult granulosa-cell tumors,
4
–
6
little is known about the pathogenesis of ovarian sex cord–stromal tumors and germ-cell tumors. Recently, germline mutations in the microRNA processing gene
DICER1
have been reported in probands with pleuropulmonary blastoma or . . .
Journal Article
Pembrolizumab plus Chemotherapy in Metastatic Non–Small-Cell Lung Cancer
The addition of pembrolizumab to chemotherapy for metastatic lung cancer without
EGFR
or
ALK
mutations resulted in better progression-free and overall survival than chemotherapy alone. Immune-related adverse effects were more common with the combination.
Journal Article
Sarcopenia as a predictor of mortality in women with breast cancer: a meta-analysis and systematic review
Background
Breast cancer is the most commonly diagnosed cancer and the leading cause of cancer death in women worldwide. Recently, studies have been published with inconsistent findings regarding whether sarcopenia is a risk factor for mortality in breast cancer patients. Therefore, the aim of this systematic review and meta-analysis was to systematically assess and quantify sarcopenia as a risk factor for mortality in breast cancer patients.
Methods
In a systematic literature review of PubMed, EMBASE, and the Cochrane CENTRAL Library, we searched for observational studies written in English (from database inception until April 30, 2019) that reported an association between sarcopenia and breast cancer in women who were 18 years or older.
Results
A total of six studies (5497 participants) were included in this meta-analysis. Breast cancer patients with sarcopenia were associated with a significantly higher risk of mortality, compared to breast cancer patients without sarcopenia (pooled HR-hazard ratio = 1.71, 95% CI: 1.25–2.33, I
2
= 59.1%). In addition, the results of age subgroup analysis showed that participants younger than 55 years with sarcopenia had a lower risk of mortality than participants aged 55 years and older with sarcopenia (pooled HR = 1.46, 95% CI: 1.24–1.72 versus pooled HR = 1.99, 95% CI: 1.05–3.78), whereas both have an increased risk of mortality compared to non-sarcopenic patients. Subgroup analyses regarding stage at diagnosis revealed an increased risk of mortality in non-metastatic patients compared to participants without sarcopenia (pooled HR = 1.91, 95% CI: 1.32–2.78), whereas the association was not significant in metastatic breast cancer patients. Other subgroup analyses were performed using different follow-up periods (> 5 years versus ≤5 years) and the results were different (pooled HR = 1.81, 95% CI: 1.23–2.65 versus pooled HR = 1.70, 95% CI: 0.80–3.62).
Conclusions
The present study found that sarcopenia is a risk factor for mortality among female early breast cancer patients. It is imperative that more research into specific interventions aimed at treating sarcopenia be conducted in the near future in order to provide evidence which could lead to decreased mortality rates in breast cancer patients.
Journal Article
Reconstruction of enhancer–target networks in 935 samples of human primary cells, tissues and cell lines
Kevin Yip and colleagues report a method for determining the target genes of enhancers in specific cells and tissues by combining global trends across many samples with sample-specific information, and considering the joint effect of multiple enhancers. They apply their method to reconstruct enhancer–target networks in 935 samples of human primary cells, tissues and cell lines.
We propose a new method for determining the target genes of transcriptional enhancers in specific cells and tissues. It combines global trends across many samples and sample-specific information, and considers the joint effect of multiple enhancers. Our method outperforms existing methods when predicting the target genes of enhancers in unseen samples, as evaluated by independent experimental data. Requiring few types of input data, we are able to apply our method to reconstruct the enhancer–target networks in 935 samples of human primary cells, tissues and cell lines, which constitute by far the largest set of enhancer–target networks. The similarity of these networks from different samples closely follows their cell and tissue lineages. We discover three major co-regulation modes of enhancers and find defense-related genes often simultaneously regulated by multiple enhancers bound by different transcription factors. We also identify differentially methylated enhancers in hepatocellular carcinoma (HCC) and experimentally confirm their altered regulation of HCC-related genes.
Journal Article
Direct band-gap crossover in epitaxial monolayer boron nitride
Hexagonal boron nitride is a large band-gap insulating material which complements the electronic and optical properties of graphene and the transition metal dichalcogenides. However, the intrinsic optical properties of monolayer boron nitride remain largely unexplored. In particular, the theoretically expected crossover to a direct-gap in the limit of the single monolayer is presently not confirmed experimentally. Here, in contrast to the technique of exfoliating few-layer 2D hexagonal boron nitride, we exploit the scalable approach of high-temperature molecular beam epitaxy to grow high-quality monolayer boron nitride on graphite substrates. We combine deep-ultraviolet photoluminescence and reflectance spectroscopy with atomic force microscopy to reveal the presence of a direct gap of energy 6.1 eV in the single atomic layers, thus confirming a crossover to direct gap in the monolayer limit.
Insulating hexagonal boron nitride (hBN) is theoretically expected to undergo a crossover to a direct bandgap in the monolayer limit. Here, the authors perform optical spectroscopy measurements on atomically thin epitaxial hBN providing indications of the presence of a direct gap of energy 6.1 eV in the single atomic layer.
Journal Article
The prevalence and influencing factors in anxiety in medical workers fighting COVID-19 in China
The coronavirus disease 2019 (COVID-19) outbreak caused by the severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2 virus) has been sustained in China since December 2019, and has become a pandemic. The mental health of frontline medical staff is a concern. In this study, we aimed to identify the factors influencing medical worker anxiety in China during the COVID-19 outbreak. We conducted a cross-sectional study to estimate the prevalence of anxiety among medical staff in China from 10 February 2020 to 20 February 2020 using the Zung Self-rating Anxiety Scale (SAS) to assess anxiety, with the criteria of normal (⩽49), mild (50–59), moderate (60–70) and severe anxiety (⩾70). We used multivariable linear regression to determine the factors (e.g. having direct contact when treating infected patients, being a medical staff worker from Hubei province, being a suspect case) for anxiety. We also used adjusted models to confirm independent factors for anxiety after adjusting for gender, age, education and marital status. Of 512 medical staff in China, 164 (32.03%) had had direct contact treating infected patients. The prevalence of anxiety was 12.5%, with 53 workers suffering from mild (10.35%), seven workers suffering from moderate (1.36%) and four workers suffering from severe anxiety (0.78%). After adjusting for sociodemographic characteristics (gender, age, education and marital status), medical staff who had had direct contact treating infected patients experienced higher anxiety scores than those who had not had direct contact (𝛽 value = 2.33, confidence interval (CI) 0.65–4.00; 𝑃 = 0.0068). A similar trend was observed in medical staff from Hubei province, compared with those from other parts of China (𝛽 value = 3.67, CI 1.44–5.89; 𝑃 = 0.0013). The most important variable was suspect cases with high anxiety scores, compared to non-suspect cases (𝛽 value = 4.44, CI 1.55–7.33; 𝑃 = 0.0028). In this survey of hospital medical workers during the COVID-19 outbreak in China, we found that study participants experienced anxiety symptoms, especially those who had direct clinical contact with infected patients; as did those in the worst affected areas, including Hubei province; and those who were suspect cases. Governments and healthcare authorities should proactively implement appropriate psychological intervention programmes, to prevent, alleviate or treat increased anxiety.
Journal Article
Gastric cancer: genome damaged by bugs
Gastric cancer (GC) is one of the leading causes of cancer-related death worldwide. The role of the microorganisms in gastric tumorigenesis attracts much attention in recent years. These microorganisms include bacteria, virus, and fungi. Among them, Helicobacter pylori (H. pylori) infection is by far the most important risk factor for GC development, with special reference to the early-onset cases. H. pylori targets multiple cellular components by utilizing various virulence factors to modulate the host proliferation, apoptosis, migration, and inflammatory response. Epstein–Barr virus (EBV) serves as another major risk factor in gastric carcinogenesis. The virus protein, EBER noncoding RNA, and EBV miRNAs contribute to the tumorigenesis by modulating host genome methylation and gene expression. In this review, we summarized the related reports about the colonized microorganism in the stomach and discussed their specific roles in gastric tumorigenesis. Meanwhile, we highlighted the therapeutic significance of eradicating the microorganisms in GC treatment.
Journal Article