CAMF: Context-Aware Message Forwarding in Mobile Social Networks

In mobile social networks (MSN), with the aim of conserving limited resources, egotistic nodes might refuse to forward messages for other nodes. Different from previous work which mainly focuses on promoting cooperation between selfish nodes, we consider it from a more pragmatic perspective in this paper. Be specific, we regard selfishness as a native attribute of a system and allow nodes to exhibit selfish behavior in the process of message forwarding. Apparently, selfishness has a profound influence on routing efficiency, and thus novel mechanisms are necessary to improve routing performance when self-centered nodes are considered. We first put forward a stateless approach to measure encounter opportunities between nodes, and represent forwarding capabilities of nodes by combining the acquired encounter opportunities with node selfishness.We then quantify receiving capabilities of nodes based on their available buffer size and energy. Taking both forwarding and receiving capabilities into account, we finally present a forwarding set mechanism, which could be deduced to a multiple knapsack problem to maximize the forwarding profit. Consequently, we take all the above studies into the design of a context-aware message forwarding algorithm (CAMF). Extensive trace-driven simulations show that CAMF outperforms other existing algorithms greatly. In fact, it achieves a surprisingly high routing performance while consumes low transmission cost and resource in MSN

Bioorthogonal Oxime Ligation Mediated in vivo Cancer Targeting

Current cancer targeting relying on specific biological interaction between the cell surface antigen and respective antibody or its analogue has proven to be effective in the treatment of different cancers; however, this strategy has its own limitations, such as the heterogeneity of cancer cells and immunogenicity of the biomacromolecule binding ligands. Bioorthogonal chemical conjugation has emerged as an attractive alternative to biological interaction for in vivo cancer targeting. Here, we report an in vivo cancer targeting strategy mediated by bioorthogonal oxime ligation. An oxyamine group, the artificial target, is introduced onto 4T1 murine breast cancer cells through liposome delivery and fusion. Poly(ethylene glycol)-polylactide (PEG-PLA) nanoparticles (NPs) are surface-functionalized with aldehyde groups as targeting ligands. The improved in vivo cancer targeting of PEG-PLA NPs is achieved through specific and efficient chemical reaction between the oxyamine and aldehyde groups

Design of ZigBee wireless sensor network system for mine gas monitoring

In view of problems of high cost, poor mobility and limited coverage of mine gas monitoring adopted by wired sensor network, a ZigBee wireless sensor network system for mine gas monitoring was designed. Sampling nodes are used to collect underground gas concentration real-timely, the collected data is transmitted to sink nodes with ZigBee protocol.After the data is gathered by the sink nodes, it is transmitted to embedded gateway. At last, the data processed by the embedded gateway is transmitted to mine monitoring center, so as to realize real-time display of mine gas concentration. The experimental results show that the system has high reliability, good real-time performance and wide coverage area

Cloning and Expression of irf7 Gene in Spotted Knifejaw (Oplegnathus punctatus) Under Virus Infection

Interferon regulatory factor (irf7) is an immune regulatory factor that plays an important role in the antiviral process. To explore the role of irf7 in Oplegnathus punctatus (Temminck & Schlegel, 1844) under viral infection, we cloned the coding DNA sequence (CDS) region of irf7 through PCR and analyzed the expression patterns at both tissue and cell levels. The results showed that the CDS region of Opirf7 was 1 332 bp and encoded a peptide with 443 amino acids. The predicted molecular weight was 50.5 kDa and the theoretical isoelectric point was 5.546. Protein structure analysis showed that Opirf7 has three conserved domains: the DNA binding domain (DBD), IRF-associated domain (IAD), and serine-rich domain (SRD). Amino acid similarity analysis showed that OpIRF7 had the highest similarity to the IRF7 of Lates calcarifer, which was 82.92%. The similarity of Opirf7 with the IRF7 of Larimichthys crocea, Paralichthys olivaceus, and Cynoglossus semilaevis were 81.99%, 79.95%, and 73.74%, respectively. Phylogenetic analysis showed that Opirf7 and other fish irf7 genes were clustered into one branch, and irf7s from Gallus gallus, Mus musculus, Macaca mulatta, and Homo sapiens were clustered into another. Tissues from healthy O. punctatus were collected, including the liver, spleen, kidney, head kidney, intestine, gill, skin, muscle, brain, heart, and blood. After RNA extraction and cDNA synthesis, real-time PCR (qPCR) was performed to detect the expression level of Opirf7 using the comparative CT method (2−ΔΔCT method). The results of qPCR showed that Opirf7 was expressed in different tissues of healthy individuals and its expression was highest in the liver, followed by the skin and intestines. The lowest expression was observed in the head kidney. In this study, the expression profiles of Opirf7 before and after viral infection were determined at the tissue and cell levels. For the in vivo challenge study, fish were intraperitoneally injected with spotted knifejaw iridovirus, and the expression level of Opirf7 was tested in the spleen, kidney, and liver. Compared with the control group at 0 h, the expression level of Opirf7 was 15-fold in the spleen and 3-fold in the kidney 4 days after infection, and the expression peak was at 7 days after infection. However, the expression of Opirf7 was not significantly altered in the liver. A poly I: C-infected O. punctatus brain cell model was established, and the expression profiles of Opirf7 mRNA were detected before and after infection. The expression of Opirf7 mRNA in the low and medium concentration groups (50 μg/mL and 100 μg/mL, respectively) increased by 13 to 17 times, and the expression level of Opirf7 mRNA in the high concentration group (200 μg/mL) increased by approximately 8 times. It was speculated that the high concentration of 200 μg/mL caused some damage to the cells and that the expression level in the high concentration group was lower than that in the low and medium groups. In this study, the full-length open reading frame sequence of Opirf7 was cloned and characterized for the first time. The deduced amino acid sequence displayed a structure similar to those of other vertebrates. Further functional analysis showed that Opirf7 has a significant response to viral infection at both tissue and cell levels. This study demonstrated that the Opirf7 gene might play an important role in the antiviral response of O. punctatus and provide a potential molecular marker for antivirus breeding of O. punctatus

Evaluating the Effects of Polyphosphoric Acid (PPA) on the Anti-Ultraviolet Aging Properties of SBR-Modified Asphalt

The ultraviolet (UV) aging of asphalt is an important factor affecting the long-term performance of asphalt pavement, especially in high altitude cold regions. The current studies have reported that styrene butadiene rubber-modified asphalt (SBRMA) has a good cracking resistance at low temperatures. In addition, polyphosphoric acid (PPA) is an effective modifier that can enhance the anti-UV aging properties of asphalt. However, the understanding of the improvement mechanism of PPA on the anti-aging of SBRMA remains unclear. Therefore, this study aimed to evaluate the effect of PPA on the UV aging resistance of SBRMA. The rheological properties of PEN90 asphalt(90#A), SBRMA, and PPA/SBR modified (PPA/SBR-MA) before and after UV aging were evaluated by dynamic shear rheometer (DSR) and bending beam rheometer (BBR) tests. The molecular weight and chemical structure of 90#A, SBRMA, and PPA/SBR-MA were determined by Fourier transform infrared spectroscopy (FTIR) and gel permeation chromatography (GPC), and the interaction and modification mechanism of the modifiers were analyzed. The rheological analysis shows that the high and low temperature performances of SBRMA are improved by adding PPA, and PPA also significantly reduces the sensitivity of SBRMA to UV aging. The microscopic test results show that PPA has a complex chemical reaction with SBRMA, which results in changes in its molecular structure. This condition enhances SBRMA with a more stable dispersion system, inhibits the degradation of the polymer macromolecules of the SBR modifier, and slows down the aging process of base asphalt. In general, PPA can significantly improve the anti-UV aging performance of SBRMA. The Pearson correlations between the aging indexes of the macro and micro properties are also significant. In summary, PPA/SBRMA material is more suitable for high altitude cold regions than SBRMA, which provides a reference for selecting and designing asphalt pavement materials in high altitude cold regions

Slc7a11 stimulates glutathione synthesis to preserve fatty acid metabolism in primary hepatocytes

ABSTRACTPrimary hepatocytes are widely used as a tool for studying metabolic function and regulation in the liver. However, the metabolic properties of primary hepatocytes are gradually lost after isolation. Here, we illustrated that fatty acid metabolism is the major compromised metabolic process in isolated primary hepatocytes, along with drastically decreased GSH and ROS content, while lipid peroxidation is increased. Gain- and loss-of-function studies revealed that Slc7a11 expression is critical in maintaining fatty acid metabolism and facilitating hormone-induced fatty acid metabolic events, which is synergistic with dexamethasone treatment. Intriguingly, Slc7a11 expression and dexamethasone treatment cooperatively upregulated AKT and AMPK signaling and mitochondrial complex expression in primary hepatocytes. Furthermore, direct treatment with reduced GSH or inhibition of ferroptosis is sufficient to drive protective effects on fatty acid metabolism in primary hepatocytes. Our results demonstrate that Slc7a11 expression in isolated primary hepatocytes induces GSH production, which protects against ferroptosis, to increase fatty acid metabolic gene expression, AKT and AMPK signaling and mitochondrial function in synergy with dexamethasone treatment, thereby efficiently preserving primary hepatocyte metabolic signatures, thus providing a promising approach to better reserve primary hepatocyte metabolic activities after isolation to potentially improve the understanding of liver biological functions from studies using primary hepatocytes