Search

In this paper, we collect 54 Gamma-Ray Burst (GRB) afterglows rebrightening in X-ray, optical, and radio bands to build the biggest sample so far, of which 18 type-Ic/b Supernova (SN)-associated GRBs have been deeply investigated. We confirm that the distribution of spectral luminosities of SN-associated GRBs has a wider scope of five orders of magnitude. After excluding short- and low-luminosity SN/GRBs, we obtain the mean light curves of high-luminosity SN/GRBs at different radio frequencies. It is found that the mean radio light curves peak twice on the tens of days and several months in each since the burst trigger. There is a time delay between radio afterglows at different frequencies, i.e. the high-frequency emissions come earlier than those low-frequency ones. We study in detail the multiband rebrightening behaviors of GRB 980425 and GRB 030329 with the most radio observation data at present. Unlike GRB 980425, the rebrightening component contributed from GRB 030329/SN 2003dh is indistinguishable. However, we predict that both SN/GRBs will produce the considerable mJy-level rebrightening emissions from their individual SN remnants on the late-times of 103th years for GRB 980425 and 64th years for GRB 030329, which is observable for the current facilities and would be detected by the forthcoming radio telescopes.

A great deal of work has carried out and get some achieved in the construction of emergency management and legal system for dealing with occupational disease accidents in China, however, the governance of occupational disease accidents is still weak in occupational health management. Based on the analysis of the situation of occupational disease accident emergency management and legal system construction at home and abroad, this paper summarizes the problems existing in the governance of occupational disease accidents, such as the need to further define the connotation and extension, the need to improve the regulations and policies, and the need to establish and improve the emergency management system. It is considered that it is very important to carry out research on the scientific definition, classification and management of occupational disease accidents.我国在应对职业病事故的应急管理和法制体系方面不断发展，但仍需加强。本文通过归纳分析国内外职业病事故应急管理和法制体系建设情况，提出我国在职业病事故治理方面存在相关内涵外延需进一步清晰界定、法规政策有待完善、应急管理机制体制需建立健全等问题，需要开展职业病事故科学界定、分类和管理等相关研究。.

We systematically analyze three GRB samples named as radio-loud, radio-quiet and radio-none afterglows, respectively. It is shown that dichotomy of the radio-loud afterglows is not necessary. Interestingly, we find that the intrinsic durations ($T_{int}$), isotropic energies of prompt gamma-rays ($E_{\gamma, iso}$) and redshifts ($z$) of their host galaxies are log-normally distributed for both the radio-loud and radio-quiet samples except those GRBs without any radio detections. Based on the distinct distributions of $T_{int}$, $E_{\gamma, iso}$, the circum-burst medium density ($n$) and the isotropic equivalent energy of radio afterglows ($L_{\nu,p}$), we confirm that the GRB radio afterglows are really better to be divided into the dim and the bright types. However, it is noticeable that the distributions of flux densities ($F_{host}$) from host galaxies of both classes of radio afterglows are intrinsically quite similar. Meanwhile, we point out that the radio-none sample is also obviously different from the above two samples with radio afterglows observed, according to the cumulative frequency distributions of the $T_{int}$ and the $E_{\gamma, iso}$, together with correlations between $T_{int}$ and $z$. In addition, a positive correlation between $E_{\gamma, iso}$ and $L_{\nu,p}$ is found in the radio-loud samples especially for the supernova-associated GRBs. Besides, we also find this positive correlation in the radio-quiet sample. A negative correlation between $T_{int}$ and $z$ is confirmed to hold for the radio-quiet sample too. The dividing line between short and long GRBs in the rest frame is at $T_{int}\simeq$1 s. Consequently, we propose that the radio-loud, the radio-quiet and the radio-none GRBs could be originated from different progenitors., Comment: 20 pages, 30 figures, submitted to MNRAS

We collect 133 Fast Radio Bursts (FRBs), including 110 non-repeating and 23 repeating ones, and systematically investigate their observational properties. To check the frequency dependence of FRB classifications, we define our samples with a central frequency below/above 1GHz as subsample I/II. We find that there is a clear bimodal distribution of pulse width for the subsample I. And If we classify FRBs into short FRBs (\emph{s}FRBs) ($$100 ms) as done for short and long Gamma-Ray Bursts (GRBs), the \emph{s}FRBs at higher central frequency are commonly shorter than those at lower central frequency not only for non-repeating but also repeating \emph{s}FRBs. Secondly, we find that fluence and peak flux density are correlated with a power law relation of $F \varpropto S{^{\gamma}_{p,obs}}$ for both \emph{s}FRBs and \emph{l}FRBs whose distributions are obviously different. Thirdly, the \emph{l}FRBs with isotropic energies ranging from $10^{42}$ to $10^{44}$ erg are more energetic than the \emph{s}FRBs in the $F- DM_{EX}$ plane, indicating that they are two representative types. Finally, it is interestingly note that the peak flux density behaves an independence on the redshift when the distance of the FRBs becomes far enough, which is similar to the scenario of peak flux evolving with redshift in the field of GRBs. We predict that fainter FRBs at higher redshift of $z>2$ can be successfully detected by FAST and SKA in the near future., Comment: 10 pages,4 figures,2 tables,accepted for publication in ApJ

Die face design of automotive panel is a tedious repeated process and depends heavily on experience of engineers, which leads to increase of lead time and production costs. An intelligent template based die face design method is presented for process reuse of automotive panel. In this method, the new part is extracted as feature parameters to match the existing process in the template library automatically and the similar process model is applied to the new part adaptively. Finally, a process reuse system for die face is developed and a typical automotive panel is employed to verify the effectiveness of the proposed method. The results show a favourable effectiveness and practicability in reducing design period and reliance on experience.

Cracking failure of butt-welded joint of 12Cr1MoV tube was comprehensively studied. Results show that both of initiation and propagation of the primary crack were circumferentially intergranular in...

Microscale strain evolution and mechanistic origin of strain localization of Inconel 718 superalloy fabricated by laser powder bed fusion was investigated. Strain maps obtained by in-situ high resolution digital image correlation (HRDIC) demonstrate that localized dislocation activities and severe strain localization occur along the coherent twin boundaries (TBs). Such localized dislocation plasticity along TBs exhibits no dependency on the elastic anisotropy and the length of TBs, and the determining factor of the occurrence of localization is the maximum Schmid factor of the TBs. By employing correlative characterizations of TBs, γ″ precipitate and dislocation slip bands, it is found out that the precipitation of V-shaped γ″ along TBs incurs the formation of precipitates denuded zones, which takes the responsibility for localized plasticity and severe strain localization at TBs.

Since the outbreak of COVID-19, it has spread rapidly throughout the country and even in the world. As a first tier city, Guangzhou is also the South Gate of China, with large population mobility and severe and complex prevention and control situation. Guangzhou CDC, together with Tencent and Alibaba Cloud, has made full use of its artificial intelligence technology to carry out a series of practices in case transmission chain analysis, close contact and other key personnel management, front-line staff prevention and control skills training and convenience services. Through the application of artificial intelligence in different scenarios, the difficulties and challenges in the prevention and control are solved, and the speed of epidemic prevention and control is increased.新型冠状病毒肺炎疫情自发生以来，在全国乃至全球迅速蔓延。广州作为一线城市，人口流动性大，防控形势严峻复杂。广州市疾病预防控制中心联合腾讯、阿里云两大科技公司，充分利用其人工智能技术，在病例传播链条分析、密切接触者等重点人员管理、一线工作人员防控技能培训和便民服务等方面开展了一系列实践。通过人工智能在不同场景下的应用，解决了防控工作中面临的困难和挑战，为疫情防控提速。.

The aim of this study was to illustrate the role of long non-coding RNA (lncRNA) DLEU1 in regulating the malignant progression of clear cell renal cell carcinoma (ccRCC) by targeting microRNA-194-5p (miRNA-194-5p).DLEU1 expression level in ccRCC tissues and para-cancerous tissues was determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The correlation between DLEU1 expression and pathological indexes of ccRCC patients was assessed. After the silence of DLUE1, the proliferative and migratory abilities of ACHN and 786-O cells were evaluated. Furthermore, Dual-Luciferase reporter gene assay and rescue experiments were conducted to identify the role of DLEU1/miRNA-194-5p in regulating the ccRCC progression in vitro.DLEU1 expression was markedly up-regulated in ccRCC tissues when compared with para-cancerous tissues. The rates of lymphatic metastasis and distant metastasis in ccRCC patients with a high level of DLEU1 were significantly higher, whereas the prognosis was significantly worse. Transfection of si-DLEU1 remarkably attenuated proliferative and migratory abilities of ACHN and 786-O cells. MiRNA-194-5p was identified as the target gene of DLEU1. In addition, the knockdown of miRNA-194-5p could reverse the regulatory effect of DLEU1 on the proliferative and metastatic abilities of ccRCC.DLEU1 is closely related to lymphatic metastasis, distant metastasis, and poor prognosis of ccRCC. It aggravates the progression of ccRCC by targeting miRNA-194-5p.

In the middle of March, the World Health Organization declared the outbreak of COVID-19 caused by SARS-CoV-2 infection a global pandemic. While China experienced a dramatic decline in daily growth rate of COVID-19, multiple importations of new cases from other countries and their related local infections caused a rapid rise. Between March 12 and April 15, we collected nasopharyngeal samples from 109 imported cases from 25 countries and 69 local cases in Guangzhou, China. In order to characterize the transmission patterns and genetic evolution of this virus among different populations, we sequenced the genome of SARS-CoV-2. The imported viral strains were assigned to lineages distributed in Europe (33.0%), America (17.4%), Africa (25.7%), or Southeast/West Asia (23.9%). Importantly, 10 imported cases from Africa formed two novel sub-lineages not identified in global tree previously. A detailed analysis showed that the imported viral strains from Philippines and Pakistan were closely related and within the same sub-lineage, whereas Ethiopia had varied lineages in the African phylogenetic tree. In spite of the diversity of imported SARS-CoV-2, 60 of 69 local infections could be traced back to two specific small lineages imported from Africa. A combined genetic and epidemiological analysis revealed a high-resolution transmission network of the imported SARS-CoV-2 in local communities, which might help inform the public health response and genomic surveillance in other cities and regions. Finally, we observed in-frame deletions on seven loci of SARS-CoV-2 genome, some of which were intra-host mutations, and they exhibited no enrichment on the S protein. Our findings provide new insight into the viral phylodynamics of SARS-CoV-2 and beta coronavirus.

Glioma is characterized by high metastasis with poor outcomes. Long non-coding RNA metastasis associated lung adenocarcinoma transcript 1 (MALAT1) was well-explored in numerous human cancers, including glioma. This study aimed to provide a novel action mechanism of MALAT1 in glioma.The expression of MALAT1, microRNA-384 (miR-384) and Golgi membrane protein 1 (GOLM1) was detected by quantitative Real-time polymerase chain reaction (qRT-PCR). The protein levels of GOLM1, light chain3 (LC3-II/LC3-I), p62, Vimentin and E-cadherin were proved by Western blot. Cell migration and invasion were monitored using the transwell assay. Bioinformatics tool starBase was used to predict target genes and associated binding sites. RNA immunoprecipitation assay (RIP) and dual-luciferase reporter assay were utilized to verify the relationship between miR-384 and MALAT1 or GOLM1. Tumor formation analysis in nude mice was conducted to ascertain the role of MALAT1 in vivo.MALAT1 was highly expressed in glioma tissues and cells. MALAT1 knockdown inhibited autophagy, migration and invasion of glioma cells. MiR-384 was a target of MALAT1, and miR-384 inhibition reversed the effects of MALAT1 knockdown in glioma cells. GOLM1 was a target of miR-384, and miR-384 inhibition eliminated the function of GOLM1 downregulation in glioma cells. In addition, GOLM1 was regulated by MALAT1 through miR-384. Moreover, MALAT1 knockdown blocked tumor growth and development in vivo.MALAT1 knockdown depleted migration and invasion by inhibiting autophagy through MALAT1/miR-384/GOLM1 axis in glioma in vitro and in vivo. The MALAT1/miR-384/GOLM1 axis was first proposed in our report, enriching the action mechanism of MALAT1 in glioma.

Glioma is a primary intracranial tumor with an unfavorable prognosis. Evolving evidence indicates that circular RNA Tau tubulin kinase 2 (circ-TTBK2) is a cancer-associated gene. Therefore, this study was to explore the potential role of circ-TTBK2.Levels of circ-TTBK2, microRNA (miR)-761, and integrin subunit beta 8 (ITGB8) were determined by adopting quantitative real-time polymerase chain reaction (qRT-PCR) or Western blot. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to detect cell viability, and the invaded cells were distinguished utilizing transwell assay. Iron and lipid reactive oxygen species (ROS) assays were implemented to examine the iron (total iron and ferrous iron) and lipid-based ROS in glioma cells, respectively. Besides, dual-luciferase reporter assay was administrated to illustrate the interaction between miR-761 and circ-TTBK2 or ITGB8. The role of circ-TTBK2 was identified via xenograft tumor model.Levels of circ-TTBK2 and ITGB8 were upregulated, whereas miR-761 level was low-expressed in glioma tissues and cells. Circ-TTBK2 was a sponge of miR-761 to modulate ITGB8. Additionally, circ-TTBK2 knockdown or miR-761 increase could retard cell proliferation, invasion, and promote ferroptosis in glioma cells. Interestingly, miR-761 inhibitor could abolish the repressive impact of circ-TTBK2 silencing on cell growth in vitro. Also, the influence of miR-761 mimic on cell phenotypes was regained after ITGB8 upregulation. Meanwhile, circ-TTBK2 deficiency caused the decrease of tumor growth.Circ-TTBK2 regulated cell proliferation, invasion and ferroptosis via targeting ITGB8 by sponging miR-761 in glioma, providing a promising biomarker for the clinical therapy of human glioma.

Metallic glasses (MGs) or amorphous alloys are an important engineering material that has a history of research of about 80–90 years. While different fast cooling methods were developed for multi-component MGs between 1960s and 1980s, 1990s witnessed a surge of research interest in the development of bulk metallic glasses (BGMs). Since then, one central theme of research in the metallic-glass community has been compositional design that aims to search for MGs with a better glass forming ability, a larger size and/or more interesting properties, which can hence meet the demands from more important applications. In this review article, we focus on the recent development of chemically complex MGs, such as high entropy MGs, with new tools that were not available or mature yet until recently, such as the state-of-the-art additive manufacturing technologies, high throughput materials design techniques and the methods for big data analyses (e.g. machine learning and artificial intelligence). We also discuss the recent use of MGs in a variety of novel and important applications, from personal healthcare, electric energy transfer to nuclear energy that plays a pivotal role in the battle against global warming.

By introducing the shape functions of virtual node polygonal (VP) elements into the standard extended finite element method (XFEM), a conforming elemental mesh can be created for the cracking process. Moreover, an adaptively refined meshing with the quadtree structure only at a growing crack tip is proposed without inserting hanging nodes into the transition region. A novel dynamic crack growth method termed as VP-XFEM is thus formulated in the framework of fracture mechanics. To verify the newly proposed VP-XFEM, both quasi-static and dynamic cracked problems are investigated in terms of computational accuracy, convergence, and efficiency. The research results show that the present VP-XFEM can achieve good agreement in stress intensity factor and crack growth path with the exact solutions or experiments. Furthermore, better accuracy, convergence, and efficiency of different models can be acquired, in contrast to standard XFEM and mesh-free methods. Therefore, VP-XFEM provides a suitable alternative to XFEM for engineering applications.

口服抗凝药包括维生素K拮抗剂和非维生素K拮抗口服抗凝药（NOAC）。国际标准化比值是监测华法林的常规实验，用于评估治疗的安全性和有效性，药物代谢基因检查需结合患者个体特征和用药情况综合分析。NOAC不需常规实验监测，在特殊或紧急临床情况下，利伐沙班、阿哌沙班、艾多沙班可使用凝血酶原时间或抗活化因子Ⅹ活性试验监测，达比加群酯可使用活化的部分凝血活酶时间、凝血酶时间、稀释凝血酶时间和蝰蛇毒凝血时间监测。廉价便捷的监测方法能为医生实施安全有效的药物调整、避免药物相关的不良事件提供可靠依据。.

To compare the epidemiologic features (e.g. settings and transmission mode) and patient clinical characteristics associated with outbreaks of different norovirus (Nov) strains, we retrospectively analysed data of Nov outbreaks occurring in Guangzhou, China from 2012 to 2018. The results suggested that outbreaks of Nov GII.2, GII.17 and GII.4 Sydney exhibited different outbreak settings, transmission modes and symptoms. GII.2 outbreaks mainly occurred in kindergartens, elementary and high schools and were transmitted mainly through person-to-person contact. By contrast, GII.4 Sydney outbreaks frequently occurred in colleges and were primarily associated with foodborne transmission. Cases from GII.2 and GII.17 outbreaks reported vomiting more frequently than those from outbreaks associated with GII.4 Sydney.

《本草纲目》是中医古代本草学集大成之作，引用文献众多，通过关键词检索，可知《本草纲目》共引用华佗相关文献30条，并存在以方名、篇名、人名作为文献出处等不规范引用之处，甚至有引文未注出处。通过文献溯源，详考各条引文内容、出处来源及版本情况，发现了长久以来困扰学者的《华佗治彭城夫人方》《华佗危病方》等文献的第一手出处，并确认《本草纲目》所引《中藏经》见于3卷本《中藏经》和转引自宋明方书，从而解决了一直以来关于华佗引文的疑问，有利于对《本草纲目》引用文献的进一步研究。.

The Jinling version of the《本草纲目》金陵本是初刻本，最能反映李时珍的原意，备受学者们的推崇，但是就其刻工技术而言，不属上乘。刻写存在许多粗疏之处，最为明显的就是缺笔讹字过多。经笔者不完全统计，此类由缺笔导致的讹字约为376个，615频次，大致可分为缺偏旁与缺笔画2类。特将2类缺笔讹字制成4个一览表，使其不仅能对《本草纲目》研究起到警示作用，还可以对古籍研究中的同类情况，发挥启示作用。.

患儿 女，系足月剖宫产出生，无窒息史。生后第5天因"阵发性青紫3 d，呼吸困难1 d"入院。口腔内可见金黄色胆汁样物，呼吸急促（70次/min），双肺大量啰音，以右侧为著。气管插管后气管导管内可见大量金黄色稀薄样物质涌出，胃肠减压管内可见透明胃液引出。经胸部CT重建、腹腔三维超声及纤维支气管镜检查确定诊断新生儿先天性支气管胆管瘘。行手术治疗，患儿康复出院。.

To investigate the values of growth differentiation factor-15 (GDF-15) level in the diagnosis of primary liver cancer and evaluation of chemotherapeutic effect.92 patients with liver cancer treated from June 2015 to May 2016 were selected as liver cancer group; 53 patients with benign liver lesion were selected as benign liver disease group, and 40 healthy subjects receiving physical examination were selected as healthy control group. Fasting venous blood was drawn from objects of study in the early morning at 1 d after admission and at the last day after chemotherapy (liver cancer group), and the serum GDF-15 level was measured.The serum GDF-15 levels in patients in liver cancer group and benign liver disease group were significantly higher than those in healthy control group and benign liver disease group (p0.05). The serum GDF-15 levels in patients with stage III and IV liver cancer were significantly higher than those in patients with stage I and II liver cancer, and the serum GDF-15 level in patients with stage IV liver cancer was significantly higher than that in patients with stage III liver cancer (p0.05). There was no significant difference in serum GDF-15 level among patients with different clinical data (p0.05). The ROC curve analysis showed that the threshold value of GDF-15 was 1573.23 ng/L, and the sensitivity, specificity, and accuracy were 81.23%, 83.99%, and 83.62%, respectively. The serum GDF-15 level in patients with progressive disease was significantly higher than those in patients with partial remission and stable disease, and the serum GDF-15 level in patients with stable disease was significantly higher than that in patients with partial remission (p0.05).The serum GDF-15 level has certain clinical values in the diagnosis of primary liver cancer and evaluation of chemotherapeutic effect.

The paper presents an algorithm combining simplex downhill search particle swarm optimization (SDSPSO) for solving reservoir operation optimization (ROO) problems, with a new search strategy: reflecting the worst particle through the particle swarm centroid to generate a new particle and guiding the evolution direction of each particle. The ROO problem is a complicated dynamically constrained nonlinear, non-convex optimization problem that is important for reservoir operation system, consisting of continuous control variables. The proposed algorithm is examined on Three Gorges Project (TGP) that provided a better operational effect result with greater effectiveness and obtains more power generation with lower insurance rate reservoir sum runoff.

Content of microbial biomass carbon was selected as indicator for identifying effects of extreme drought on agriculture soil ecosystem. Through a series of prototype observation experiments, changing tendencies of microbial biomass carbon content and the proportion of microbial biomass carbon in soil organic carbon were identified. The optimum mass water content of soil for microbial biomass carbon was 19.5% and the demarcation point of microbial biomass carbon to drought was 14.3%, which could be used to demonstrate alters and degradation of soil ecosystem as well as the irrigation requirement of crops. We evaluated sustainability of different drought soil ecosystems after experiencing rainstorm with rehabilitation. The results suggested that soil ecosystem which was interfered by moderate drought could recover and its tolerance to drought was improved, as well as its function and activity. Soil ecosystem could barely recover from severe drought and could not adapt to severe drought stress. Soil ecosystem could not restore from extreme drought within a few days, the function and structure were damaged. We came to the conclusion that mass water content of soil should kept above 10% to avoid destroying function and structure while soil ecosystem would better be watered when mass water content was lower than 14.3% in order to maintain high productivity.