The assembly of sequence-specific enhancer-binding transcription factors (TFs) at cis-regulatory elements in the genome has long been regarded as the fundamental mechanism driving cell type-specific ...gene expression. However, despite extensive biochemical, genetic, and genomic studies in the past three decades, our understanding of molecular mechanisms underlying enhancer-mediated gene regulation remains incomplete. Recent advances in imaging technologies now enable direct visualization of TF-driven regulatory events and transcriptional activities at the single-cell, single-molecule level. The ability to observe the remarkably dynamic behavior of individual TFs in live cells at high spatiotemporal resolution has begun to provide novel mechanistic insights and promises new advances in deciphering causal-functional relationships of TF targeting, genome organization, and gene activation. In this review, we review current transcription imaging techniques and summarize converging results from various lines of research that may instigate a revision of models to describe key features of eukaryotic gene regulation.
Flexible electronics have gained considerable research interest in the recent years because of their special features and potential applications in flexible displays, artificial skins, sensors, ...sustainable energy,
etc.
With unique geometry, outstanding electronic/optoelectronic properties, excellent mechanical flexibility and good transparency, inorganic nanowires (NWs) offer numerous insights and opportunities for flexible electronics. This article provides a comprehensive review of the inorganic NW based flexible electronics studied in the past decade, ranging from NWs synthesis and assembly to several important flexible device and energy applications, including transistors, sensors, display devices, memories and logic gates, as well as lithium ion batteries, supercapacitors, solar cells and generators. The integration of various flexible nanodevices into a self-powered system was also briefly discussed. Finally, several future research directions and opportunities of inorganic NW flexible and portable electronics are proposed.
This review summarizes the latest research for exploiting the flexible electronic applications of inorganic nanowires.
Introduction: As an advanced agricultural technology equipment, the functional integration design and appearance aerodynamic characteristics of hexacopter agricultural UAV are significant for ...improving the efficiency of agricultural production. Methods: Firstly, the study carried out the functional integration design of the hexacopter agricultural UAV, and completed the matching analysis and selection of the relevant components of the power system. Then, the numerical simulation method of computational fluid dynamics was used to analyze the aerodynamic characteristics of the UAV. Finally, the role of different propeller pitch on important parameters such as lift and range time of the UAV was verified. Results and discussion: The results showed that in the XY section of the UAV, namely, the surface parallel to the flight direction, the areas with high streamline velocity were mainly concentrated at the intersection of the airflow with the landing gear and the motor. The streamlines in the front of the UAV were tightly and neatly distributed, while those in the rear were sparser. The motor force efficiencies of the UAVs with different propeller pitches ranged from 7.05 to 7.25 g/w. At a flight speed of 5 m/s, the motor force effect of the UAV with a pitch of 260 mm reached 7.25 g/w, which was the highest value among all models. Meanwhile, it had the longest endurance time of 19.14 min, indicating the best performance. The results suggested that it not only promoted the modernization of agricultural UAVs but also effectively enhanced the efficiency of agricultural production.
Cloud computing has become prevalent due to its nature of massive storage and vast computing capabilities. Ensuring a secure data sharing is critical to cloud applications. Recently, a number of ...identity-based broadcast proxy re-encryption (IB-BPRE) schemes have been proposed to resolve the problem. However, the IB-BPRE requires a cloud user (Alice) who wants to share data with a bunch of other users (e.g., colleagues) to participate the group shared key renewal process because Alice's private key is a prerequisite for shared key generation. This, however, does not leverage the benefit of cloud computing and causes the inconvenience for cloud users. Therefore, a novel security notion named revocable identity-based broadcast proxy re-encryption (RIB-BPRE) is presented to address the issue of key revocation in this work. In a RIB-BPRE scheme, a proxy can revoke a set of delegates, designated by the delegator, from the re-encryption key. The performance evaluation reveals that the proposed scheme is efficient and practical.
•Address the problem of low response rate in social Q&A that happens on a Chinese microblogging site.•Propose 17 factors from both the questioner and the question's perspectives and investigate their ...effectiveness in determine whether or not a question will be answered.•Build a model to differentiate questions with high probabilities of being responded from those with low probabilities of being answered, which achieved a prediction accuracy of 74%.•Our results show that whether or not a question will be answered depend more on the questioner than the question.•Propose the potential implication of improving visibility of users with low social capital to increase their question's response probability.
With the noted popularity of social networking sites, people increasingly rely on these social networks to address their information needs. Although social question and answering is potentially an important venue seeking information online, it, unfortunately, suffers from a problem of low response rate, with the majority of questions receiving no response. To understand why the response rate of social question and answering is low and hopefully to increase it in the future, this research analyzes extrinsic factors that may influence the response probability of questions posted on Sina Weibo. We propose 17 influential factors from 2 different perspectives: the content of the question, and the characteristics of the questioner. We also train a prediction model to forecast a question's likelihood of being responded based on the proposed features We test our predictive model on more than 60,000 real-world questions posted on Weibo, which generate more than 600,000 responses. Findings show that a Weibo's question answerability is primarily contingent on the questioner versus the question. Our findings indicate that using appreciation emojis can increase a question's response probability, whereas the use of hashtags negatively influences the chances of receiving answers. Our contribution is in providing insights for the design and development of future social question and answering tools, as well as for enhancing social network users’ collaboration in supporting social information seeking activities.
Effects of dietary supplemental stachyose on caecal skatole concentration, hepatic cytochrome P450 (CYP450, CYP) mRNA expressions and enzymatic activities in broilers were evaluated. Arbor Acre ...commercial mixed male and female chicks were assigned randomly into six treatments. The positive control (PC) diet was based on maize–soyabean meal, and the negative control (NC) diet was based on maize–non-soyabean meal. The NC diet was then supplemented with 4, 5, 6 and 7 g/kg stachyose to create experimental diets, named S-4, S-5, S-6 and S-7, respectively. Each diet was fed to six replicates of ten birds from days 1 to 49. On day 49, the caecal skatole concentrations in the PC, S-4, S-5, S-6 and S-7 groups were lower than those in the NC group by 42·28, 23·68, 46·09, 15·31 and 45·14 % (P < 0·01), respectively. The lowest pH value was observed in the S-5 group (P < 0·05). The stachyose-fed groups of broilers had higher caecal acetate and propionate levels compared with control groups, and propionate levels in the S-6 and S-7 groups were higher than those in the S-4 and S-5 groups (P < 0·001). The highest CYP3A4 expression was found in the S-7 group (P < 0·05), but this was not different from PC, S-4, S-5 and S-6 treatments. There was no significant difference in CYP450 (1A2, 2D6 and 3A4) enzymatic activities among the groups (P > 0·05). In conclusion, caecal skatole levels can be influenced by dietary stachyose levels, and 5 g/kg of stachyose in the diet was suggested.
Double primary support structures could effectively solve the problem of large deformation of surrounding rock for soft rock tunnels. However, the mechanical behavior of this new support structure is ...still incomplete, and the design method should be revised. Based on the theory of energy conversion, this paper analyzes the support characteristic curve of double primary support and puts forward the dynamic design method of double primary support. Considering that the secondary lining can be set after monitoring the deformation amount and deformation rate of the first primary support, its support parameters can be dynamically adjusted according to the actual situation. By applying the double primary support design method in the Maoxian tunnel of Chenglan Railway, the field monitoring results show that the double primary support has a significant effect on the energy release of surrounding rocks, greatly reducing the load acting on the secondary lining and ensuring the safety and reliability of the tunnel structure.
A cluster of pneumonia (COVID‐19) cases have been found in Wuhan China in late December, 2019, and subsequently, a novel coronavirus with a positive stranded RNA was identified to be the aetiological ...virus (severe acute respiratory syndrome coronavirus 2, SARS‐CoV‐2), which has a phylogenetic similarity to severe acute respiratory syndrome coronavirus (SARS‐CoV). SARS‐CoV‐2 transmits mainly through droplets and close contact and the elder or people with chronic diseases are high‐risk population. People affected by SARS‐CoV‐2 can be asymptomatic, which brings about more difficulties to control the transmission. COVID‐19 has become pandemic rapidly after onset, and so far the infected people have been above 2 000 000 and more than 130 000 died worldwide according to COVID‐19 situation dashboard of World Health Organization (https://covid19.who.int). Here, we summarized the current known knowledge regarding epidemiological, pathogenesis, pathology, clinical features, comorbidities and treatment of COVID‐19/ SARS‐CoV‐2 as reference for the prevention and control COVID‐19.
Quantifying source-oriented risk can identify primary pollution sources to help alleviate risks to ecosystems and human health posed by soil heavy metals. Taking Yulin National Energy and Chemical ...Industry Base as an example, ecosystem and human health risk assessments of each identified source category were quantitatively calculated by combining the Potential Ecological Risk (RI) and Total Carcinogenic Risk (Total-CR)/Total Hazard Index (Total-HI) assessment models with the positive matrix factorization (PMF) receptor model. In this work, an analysis of the Geoaccumulation Index (Igeo), Contamination Index (Pi), RI, CR and HI of heavy metals (As, Cr, Cu, Zn, Cd, Pb, Hg and Mn) identified universal ecosystem risks and both carcinogenic and noncarcinogenic health risks in most sites. Source apportionment results indicated that the dominant source of heavy metals in the soil was coal-related activities (52.5%), followed by industrial activities (22.0%), traffic activities (13.2%) and agricultural activities (12.3%). The source-oriented quantitative risk assessment results showed that coal-related activities are the greatest contributor to RI and Total-HI, while industrial activities are the largest source of Total-CR, which should be controlled, to reduce the carcinogenic health risk posed by exposure to heavy metals.
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•The level of heavy metals in soils from Yulin were investigated.•Igeo, Pi, RI, CR and HI values in soil indicated high risk to ecological and human health.•Four source categories were identified using PMF model.•Source contributions to ecological and human health risks were quantitatively and spatially identified.•Coal-related activities caused the greatest potential ecological risk and hazard index.
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