In recent years, we witnessed a drastic increase of ransomware, especially on popular mobile platforms including Android. Ransomware extorts victims for a sum of money by taking control of their ...devices or files. In light of their rapid growth, there is a pressing need to develop effective countermeasure solutions. However, the research community is still constrained by the lack of a comprehensive data set, and there exists no insightful understanding of mobile ransomware in the wild. In this paper, we focus on the Android platform and aim to characterize existing Android ransomware. Specifically, we have managed to collect 2,721 ransomware samples that cover the majority of existing Android ransomware families. Based on these samples, we systematically characterize them from several aspects, including timeline and malicious features. In addition, the detection results of existing anti-virus tools are rather disappointing, which clearly calls for customized anti-mobile-ransomware solutions. To detect ransomware that extorts users by encrypting data, we propose a novel real-time detection system, called RansomProber. By analyzing the user interface widgets of related activities and the coordinates of users' finger movements, RansomProber can infer whether the file encryption operations are initiated by users. The experimental results show that RansomProber can effectively detect encrypting ransomware with high accuracy and acceptable runtime performance.
A highly controlled ring opening of siloxydifluorocyclopropanes, formed by nBuN4Br-catalyzed difluorocyclopropanation of methyl vinyl ketones bearing a β-alkylthio group by using TMSCF2Br as a unique ...difluorocarbene source, results in metal difluorohomoenolates with assistance of copper or silver followed by an intramolecular addition and elimination reaction leading to α-gem-difluorocyclopentenones efficiently.
Piezotronic and piezo-phototronic are two emerging fields of flexible electronics and nanoelectronics using by piezoelectric semiconductor materials, such as ZnO, GaN, InN and CdS. Recent experiments ...shown piezoelectric and semiconductor properties of monolayer MoS2, which have been applied as nanogenertor and piezotronic transistor. Two-dimensional piezoelectric semiconductor can be utilized for high-performance photovoltaic devices. In this paper, a two-dimensional material piezo-phototronic solar cell is studied theoretically based on a monolayer MoS2 metal-semiconductor contact. The current-voltage characteristics, open circuit voltage, maximum output power, fill factor and power conversion efficiency have been studied for the piezo-phototronic solar cell. The modulation level of piezo-phototronic effect is presented to evaluate the performance under applied strain. The piezo-phototronic effect can increase the open circuit voltage 5.8% at strain of 1%. This principle can be a new way to develop high-performance two-dimensional solar cells.
Monolayer MoS2 shows piezoelectric and semiconductor properties in recent experiments, which have been used for nanogenertor and piezotronic transistor. Two-dimensional piezoelectric semiconductor can be applied for piezo-phototronic solar cell. The modulation by piezo-phototronic effect can enhance the performance of monolayer MoS2 solar cells. Display omitted
•Two-dimensional piezo-phototronic solar cells can be a high-performance, tunable photovoltaic device under strain.•The piezo-phototronic effect can increase the open circuit voltage 5.8% at strain of 1%.•The theoretical model provides a feasible structure of two dimensional piezo-phototronic solar cells.
Smart sensor-equipped mobile devices sense, collect, and process data generated by the edge network to achieve intelligent control, but such mobile devices usually have limited storage and computing ...resources. Mobile cloud storage provides a promising solution owing to its rich storage resources, great accessibility, and low cost. But it also brings a risk of information leakage. The encryption of sensitive data is the basic step to resist the risk. However, deploying a high complexity encryption and decryption algorithm on mobile devices will greatly increase the burden of terminal operation and the difficulty to implement the necessary privacy protection algorithm. In this paper, we propose ENSURE (EfficieNt and SecURE), an efficient and secure encrypted search architecture over mobile cloud storage. ENSURE is inspired by edge computing. It allows mobile devices to offload the computation intensive task onto the edge server to achieve a high efficiency. Besides, to protect data security, it reduces the information acquisition of untrusted cloud by hiding the relevance between query keyword and search results from the cloud. Experiments on a real data set show that ENSURE reduces the computation time by 15% to 49% and saves the energy consumption by 38% to 69% per query.
Transitional metal oxides (TMO) exhibit well electrocatalytic performance for oxygen evolution reaction (OER) and have the potential to replace the noble metal electrocatalysts. However, how to ...further increase the number of catalytic active sites and improve the electrocatalytic activity in alkaline solution is always a great challenge. Therefore, it is necessary to develop high-performance OER electrocatalysts. Herein, the coupled interfacial nanostructure of Fe3O4 and CoO was successfully supported on carbon nanotubes (CNTs) as a highly efficient OER electrocatalyst (denoted as Fe3O4/CoO CNTs) through a simple and feasible two-step synthesis strategy. It is found that the electrocatalyst Fe3O4/CoO CNTs shows remarkable electrocatalytic activity toward OER with a low overpotential of 270 mV (i.e., 1.50 V vs reversible hydrogen electrode) at the current density of 10 mA cm–2 and a small Tafel slope of 59 mV dec–1 in basic media. Additionally, it presents superior electrochemical stability for over 45 h. The outstanding OER performance of the electrocatalyst is mainly derived from the coupled interfacial nanostructure between Fe3O4 and CoO, which promotes the improvement of the electronic structure, increases the number of catalytic active sites, and creates abundant oxygen vacancies. Our work provides a good choice for the future application of TMO-based electrocatalysts in water splitting.
A silver-catalyzed, defluorination ring-opening diarylation of siloxy 2,2-difluorocyclopropanes, with two arenes, to directly prepare polysubstituted 2-fluoroallylic compounds, is described. This ...multicomponent reaction proceeds smoothly in good stereoselectivity, which is due to a chelation-controlled addition of arenes to α-fluorinated ketone intermediate.
Vascular endothelial growth factor (VEGF) is a secreted mitogen associated with angiogenesis and re-vascularization of spinal cord injury (SCI). VEGF has long been thought to be a potent neurotrophic ...factor for the survival of spinal cord neuron. However, the neuroprotective mechanism of VEGF is still unclear. The aim of this study was to investigate the effect of VEGF on spinal cord injury and its mechanisms. Young male Wistar rats were subjected to SCI and then VEGF165 were injected directly into the lesion epicenter 24 h post injury. We detected Basso, Beattie and Bresnahan (BBB) scores and numbers of motor neuron via Nissl staining. The expressions of autophagy related protein Beclin1 and LC3B were determined by Western blot and RT-PCR. We also detected the contents of inflammation factors interleukin-1β (IL-1β), tumor necrosis factor alpha (TNF-α) and interleukin-10(IL-10) in LPS (Lipopolysaccharide) treated spinal neuron-glia co-culture by ELISA. We found that VEGF165 administration increased the BBB score and reduced the loss of motor neuron of rats induced by SCI. VEGF decreased the protein expressions of IL-1β, TNF-α and IL-10 and up-regulated the expressions of Beclin1 and LC3B of rats. In the in vitro study, VEGF165 decreased the levels of IL-1β, IL-10 and TNF-a in the medium of LPS treated spinal neuron-glia co-culture, which was partially blocked by 3-MA, the inhibitor of autophagy. In addition, VEGF165 up-regulate the expressions of Beclin1 and LC3B in co-culture cells. The results suggested that VEGF165 attenuated the spinal cord injury by inhibiting the inflammation and increasing the autophagy function.
•VEGF inhibits inflammation through activating autophagy in vitro or in vivo.•VEGF attenuated neuron loss of SCI and improved neurobehavior function.•Neuronal protective effect of VEGF may have interaction with autophagy.
Curcumenol, an effective ingredient of Wenyujin, has been reported that exerted its antitumor potential in a few cancer types. However, the effect and molecular mechanism of curcumenol in lung cancer ...are largely unknown. Here, we found that curcumenol induced cell death and suppressed cell proliferation in lung cancer cells. Next, we demonstrated that ferroptosis was the predominant method that contributed to curcumenol-induced cell death of lung cancer in vitro and vivo for the first time. Subsequently, using RNA sequencing, we found that the long non-coding RNA H19 (lncRNA H19) was significantly downregulated in lung cancer cells treated with curcumenol, when compared to untreated controls. Overexpression of lncRNA H19 eliminated the anticancer effect of curcumenol, while lncRNA H19 knockdown promoted ferroptosis induced by curcumenol treatment. Mechanistically, we showed that lncRNA H19 functioned as a competing endogenous RNA to bind to miR-19b-3p, thereby enhanced the transcription activity of its endogenous target, ferritin heavy chain 1 (FTH1), a marker of ferroptosis. In conclusion, our data show that the natural product curcumenol exerted its antitumor effects on lung cancer by triggering ferroptosis, and the lncRNA H19/miR-19b-3p/FTH1 axis plays an essential role in curcumenol-induced ferroptotic cell death. Therefore, our findings will hopefully provide a valuable drug for treating lung cancer patients.
Display omitted
•Curcumenol exhibited its anticancer activity by triggering ferroptosis both in vitro and in vivo.•Loss of lncRNA H19 leads to ferroptotic cell death in lung cancer.•LncRNA H19 plays an important role in curcumenol-induced ferroptotic cell death in lung cancer.•Curcumenol induced ferroptosis through a ceRNA network based on lncRNA H19/miR-19b-3p/FTH1 axis.
Obesity and metabolic disorders have gradually become public health-threatening problems. The metabolic disorder is a cluster of complex metabolic abnormalities which are featured by dysfunction in ...glucose and lipid metabolism, and results from the increasing prevalence of visceral obesity. With the core driving factor of insulin resistance, metabolic disorder mainly includes type 2 diabetes mellitus (T2DM), micro and macro-vascular diseases, non-alcoholic fatty liver disease (NAFLD), dyslipidemia, and the dysfunction of gut microbiota. Strategies and therapeutic attention are demanded to decrease the high risk of metabolic diseases, from lifestyle changes to drug treatment, especially herbal medicines. Indole is a parent substance of numerous bioactive compounds, and itself can be produced by tryptophan catabolism to stimulate glucagon-like peptide-1 (GLP-1) secretion and inhibit the development of obesity. In addition, in heterocycles drug discovery, the indole scaffold is primarily found in natural compounds with versatile biological activity and plays a prominent role in drug molecules synthesis. In recent decades, plenty of natural or synthesized indole deriviatives have been investigated and elucidated to exert effects on regulating glucose hemeostasis and lipd metabolism. The aim of this review is to trace and emphasize the compounds containing indole scaffold that possess immense potency on preventing metabolic disorders, particularly T2DM, obesity and NAFLD, along with the underlying molecular mechanisms, therefore facilitate a better comprehension of their druggability and application in metabolic diseases.
Display omitted
•Indole scaffold was introduced in this review as a privileged structure in drug design for alleviating diabetes.•Indole alkaloids have potential in preventing metabolic disorders, including diet-induced obesity and fatty liver disease.•Mechanism studies of antidiabetic synthesized indoles indicated that these molecules act via various targets.
PDF
