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With the popularization of IoT devices, more and more valuable data is generated.Analyzing and mining big data based on IoT devices has become a hot topic in the academic and industrial circles in recent years.However, due to the lack of necessary detection and protection methods, many IoT devices have serious information security risks.In particular, device hard-coded information is closely related to system encryption and decryption, identity authentication and other functions, which can provide confidentiality protection for core data.Once this information is exploited by malicious attackers, serious consequences such as sensitive information leakage, backdoor attacks, and unauthorized logins will occur.In response to this problem, a multi-type character recognition and positioning scheme was designed and a hard-coded vulnerability detection method in executable files was proposed based on the study of the characteristics of hard-coded vulnerabilities in IoT devices.The proposed method extracted the firmware of IoT devices and filtered all executable files as the source to be analyzed.Then, a solution to identify and locate three types of hard-coded characters was provided.Further, the reachability of the function, where the hard-coded character was located, was analyzed according to the function call relationship.Meanwhile, the instruction heterogeneity was mitigated by an intermediate representation (IR) model.The character and parameter hard-coded values was obtained through a data flow analysis approach.A symbolic execution method was devised to determine the trigger conditions of the hard-coded vulnerabilities, and then the vulnerability detection result was output.On the one hand, the proposed method introduced the method of symbolic execution based on the use of the intermediate representation model, which eliminated the dependency of instruction architecture and reduces the false positive rate of vulnerabilities; On the other hand, this method can integrate characters, files, and cryptographic implementation to realize the different characteristics of three types of hard-coded characters, which increased the coverage of vulnerability detection and improves the versatility of the detection method.The experimental results show that the proposed method can effectively detect three types of hard-coded vulnerabilities of characters, files and cryptographic implementation in various IoT devices, and has good detection accuracy, which can provide certain guidance for the deployment of subsequent security protection technologies.

Although dearomative functionalizations enable the direct conversion of flat aromatics into precious three‐dimensional architectures, the case for simple arenes remains largely underdeveloped owing to the high aromatic stabilization energy. We herein report a dearomative sequential addition of two nucleophiles to arene π‐bonds through umpolung of chromium–arene complexes. This mode enables divergent dearomative carbonylation reactions of benzene derivatives by tolerating various nucleophiles in combination with alcohols or amines under CO‐gas‐free conditions, thus providing modular access to functionalized esters or amides. The tunable synthesis of 1,3‐ or 1,4‐cyclohexadienes as well as the construction of carbon quaternary centers further highlight the versatility of this dearomatization. Diverse late‐stage modifications and derivatizations towards synthetically challenging and bioactive molecules reveal the synthetic utility. A possible mechanism was proposed based on control experiments and intermediate tracking. [ABSTRACT FROM AUTHOR]

It is of great significance to characterize the dynamics of underwater explosive bubbles in close proximity to mutually perpendicular walls for ensuring the safety of important underwater structures. In this paper, a dynamic experiment on underwater explosion bubbles was carried out near constructed mutually perpendicular walls. High-speed cameras were utilized to capture high-resolution images, while pressure sensors recorded pressure–time history curves. The main focus was on studying the evolution process of bubble morphology and pulse characteristics. When the position of the charge's center relative to the horizontal wall remained fixed, decreasing the distance between the charge's center and the vertical wall resulted in a reduction in the equivalent maximum radius of bubbles and an increase in its pulsation period. Additionally, the asymmetric collapse of bubbles on a single wall transformed into asynchronous collapse on two walls, with most collapsed bubbles tending to migrate and expand toward the corner formed by mutually perpendicular walls. The resulting jet from the collapse of bubbles exhibited deflection toward the vertical wall, with an inclination angle increasing approximately proportionally with dimensionless distance ratio γ h / γ v . Moreover, it became more difficult for achieving effective focusing of bubble energy as the jet approached the corners formed by mutually perpendicular walls. The experiments also implied that reducing the dead weight of the vertical wall weakened its contact with the horizontal wall, causing an increase in the equivalent maximum radius of bubbles and jet inclination, as well as a decrease in the bubble pulsation period, under the same dimensionless distance γ v . [ABSTRACT FROM AUTHOR]

Objective To investigate the value of new ultrasonographic teaching pattern in the urological integrated teaching course for 4+4 medical education pilot class of Peking Union Medical College (PUMC), and optimize future improvements based on teaching feedbacks. Methods Four themes were set up in the new ultrasonographic teaching pattern, including theory combined with ultrasonographic images and videos teaching, human ultrasonographic practice teaching, ultrasonographic simulation teaching and ultrasonographic case discussion. After the class, feedbacks from students were collected through questionnaire survey and the data was analyzed. Results The survey results showed that the multiple-model methods were well accepted by students. However, current teaching content and class hours were not enough to meet students' needs. Conclusions Increasing the input of ultrasonographic education is suggested for future improvement of imaging teaching at PUMC. Furthermore, establishing a more reasonable and hierarchical ultrasonographic teaching schedule based on the clinical teaching needs and students' learning capacity improve the learning outcomes of an integrated teaching.

Climate change and human activities are important causes of runoff changes in watersheds. The Budyko hydrothermal coupled equilibrium equation is a common tool for runoff change analysis, because it takes into account certain physical causes on the one hand, and the parameters of the equation are simple on the other hand, so it has been widely used in runoff change attribution for a long time. However, the current research and application of Budyko' s formula for time-varying forms still need to be strengthened. Therefore, this paper first analyzes the trend and abrupt change of annual runoff in the study area by Mann-Kendall test and abrupt change test, and then constructs the time- varying Budyko formula based on the principle of hydrothermal coupling equilibrium, including linear, quadratic polynomial and physical mechanism, and uses Nash efficiency coefficient as the evaluation index to verify the most suitable. Finally, the contribution of precipitation, potential evapotranspiration and human activities to the runoff change is calculated, and the attribution analysis of the runoff change in the Liudong River basin is carried out. The results of this study show that the runoff of the river basin has been decreasing in recent years with the impact of climate change, with a significant change in 1997. A comparison of the sensitivity of precipitation, potential evapotranspiration and human activities to runoff show that the decrease in precipitation is the dominant factor in the decrease in runoff, with a contribution of 49%. Meanwhile, with the development of human economy and society and the construction of large water conservancy facilities, the influence of human activities on runoff changes in the basin is gradually emerging, with a contribution rate of about 26%. [ABSTRACT FROM AUTHOR]

HIF-1[alpha], one of the most extensively studied oncogenes, is activated by a variety of microenvironmental factors. The resulting biological effects are thought to depend on its transcriptional activity. The RNAse enzyme Dicer is frequently downregulated in human cancers, which has been functionally linked to enhanced metastatic properties; however, current knowledge of the upstream mechanisms regulating Dicer is limited. In the present study, we identified Dicer as a HIF-1[alpha]-interacting protein in multiple types of cancer cell lines and different human tumors. HIF-1[alpha] downregulated Dicer expression by facilitating its ubiquitination by the E3 ligase Parkin, thereby enhancing autophagy-mediated degradation of Dicer, which further suppressed the maturation of known tumor suppressors, such as the microRNA let-7 and microRNA-200b. Consequently, expression of HIF-1[alpha] facilitated epithelial-mesenchymal transition (EMT) and metastasis in tumor-bearing mice. Thus, this study uncovered a connection between oncogenic HIF-1[alpha] and the tumor-suppressive Dicer. This function of HIF-1[alpha] is transcription independent and occurs through previously unrecognized protein interaction-mediated ubiquitination and autophagic proteolysis., Introduction HIF-1[alpha] is one of the best-studied oncogenes and it transcriptionally regulates genes to facilitate cancer metastasis (1, 2). Although HIF-1[alpha] accumulation was originally identified under hypoxia, as implied by [...]