Chemical and Biochemical Hydrolysis of Persian Sturgeon (Acipenser persicus) Visceral Protein

Chemical (pH 3.3, 70 °C, 85 °C; pH 12, 70 °C, 85 °C) and biochemical (Alcalase, Protamex, Neutrase, Flavourzyme, and Trypsin) hydrolysis of Persian sturgeon (Acipenser persicus) visceral protein was investigated. The results of this study revealed that there are significant differences between enzymes in terms of degree of hydrolysis (DH%; P < 0.05). Alcalase-hydrolyzed fish protein had the highest DH% (50.13%), and Trypsin-hydrolyzed fish protein had the minimum DH% (14.21%). The highest DH% in chemical hydrolysis was related to pH 3.3 at 85 °C (68.87%). The highest protein recovery (83.64%) and protein content (73.34) were related to enzymatic hydrolysis by Alcalase. The results of current study showed the significant effect of hydrolysis conditions on fish protein hydrolysate properties. Microbial enzymes could produce fish hydrolysates with higher degree of hydrolysis when compared to animal enzyme. Also, in chemical hydrolysis it is clear that hydrolysis at the lower pH and at higher temperature causes to more protein recovery and degree of hydrolysis.     

Improving the dyeability of polypropylene fabrics using laser technology

In this research work, dyeability of polypropylene (PP) fabrics due to laser irradiation was studied. The laser intensities used during the experiments were 3, 3.8, 4.2, and 4.8?W?cm^?2. The morphology of the modified surfaces was investigated using scanning electron microscopy. Also, Fourier transform infrared spectroscopy was used to examine the functional groups of the corresponding samples. For the dyeing process, aqueous solutions, containing 3.0?wt.% of the Astrazon Red Violet 3RN (CI Basic Violet 16) dye, were employed. For comparing the amount of fabrics dye exhaustion, reflective spectrophotometer was used. Also, light and wash fastnesses of dyed samples were measured. The results show a significant increase in the color depth upon dyeing after treating PP fabrics with CO₂ laser.     

Antibacterial activity of PVA-based nanofibers loaded with silver sulfadiazine/cyclodextrin nanocapsules

Silver sulfadiazine (SSD) is a highly insoluble drug in water with a significant antibacterial activity. Supramolecular nanocontainers of cyclodextrins (β-CD or HPβ-CD)/SSD were prepared by inclusion complex (IC) forming between CDs and SSD at various conditions. Solubility, bioavailability and in vitro dissolution of obtaining SSD were investigated and the results showed of SSD in CDs that solubility improved and its release is controllable by encapsulation cavity. Electro-spun nanofibers of PVA containing SSD/CDs inclusion complex showed significant antibacterial effect against Escherichia coli and Staphylococcus aureus, which are related to SSD     

基于非对称信道状态信息的协作通信：一种契约理论建模方法

In relay-assisted cooperative com-munication, relay nodes help forwarding the information of a source node in case of link failure between the source and a destination. Although user cooperation improves the over-all efficiency of the network, it requires incen-tive to stimulate potential relay nodes to assist the source by forwarding its data to the desti-nation. Moreover, the potential relays are bet-ter informed than the source about their chan-nel conditions to destination, which results in asymmetric information between the source and the relays. In this paper, we study the problem of lack of forwarding incentive in cooperative communication when channel state information of relays is private infor-mation and not known by the source. To tackle this problem, we apply the principle of contract theory to a cooperative wireless system. Source first designs incentive compatible and individually rational contract, consisting of a set of power-credit pairs. Then it broadcasts contract items to nearby nodes. Once the source node receives reply messages from the volunteer relays, it chooses one or more relays based on its re-quirements and communication starts. Simulation results show how credit assignment works in order to stimulate relays to cooperate and prevents relays from cheating behavior.     

Enhancing EAP-TLS authentication protocol for IEEE 802.11i

IEEE 802.11i authentication framework is composed of the 802.1x and an extensible authentication protocol (EAP) mechanism. One of the most applicable techniques in the EAP methods is EAP-transport layer security (EAP-TLS). The EAP-TLS implementation issues are high execution time; high number of data exchanges between two parties and possibility of closing connection as a result of modification in the contents of the handshake messages, which are all addressed in this paper. This research analyses the EAP-TLS in WLANs to improve this method’s efficiency in terms of the security analysis, time and memory usage. Based on the results, this research proposes an enhanced method with a discrete cryptographic mechanisms and a distinct handshake structure, which reduces the number of steps in the handshake protocol. This enhanced method also provides robust security compared to the original EAP-TLS with approximately the same level of memory usage, which reduces execution time significantly.     

面向驾驶员的个性化健康导航

为了减少因驾驶员的生理和心理健康状况变化引发的交通事故,实现对驾驶员健康状态的自动监测和实时优化,提出以控制论的基本理论为基础的驾驶员健康状态闭环反馈系统框架.首先基于驾驶员日志建立个性化健康模型;然后结合各种传感器实时采集的驾驶员、车辆和道路环境等多模态数据,对驾驶员当前健康状态进行估计;最后针对预设健康目标,为驾驶员提供可执行的行为建议,实现对驾驶员健康状态的导航优化.在最关键的实时监测环节,提出基于注意力的卷积神经网络(convolutional neural network, CNN)-长短期记忆网络(long short term memory, LSTM)的多模态融合模型,实现对驾驶员压力、情绪和疲劳3个方面的健康状态估计.在私有数据集和公开数据集上分别开展的实验验证均获得高于90%的检测准确率.实验结果表明,提出的模型和方法可以实时准确监测驾驶员的压力、情绪和疲劳状态,为实现驾驶员的个性化健康导航系统提供有力支撑.     

A Model‐Based Image Steganography Method Using Watson's Visual Model

This paper presents a model‐based image steganography method based on Watson's visual model. Model‐based steganography assumes a model for cover image statistics. This approach, however, has some weaknesses, including perceptual detectability. We propose to use Watson's visual model to improve perceptual undetectability of model‐based steganography. The proposed method prevents visually perceptible changes during embedding. First, the maximum acceptable change in each discrete cosine transform coefficient is extracted based on Watson's visual model. Then, a model is fitted to a low‐precision histogram of such coefficients and the message bits are encoded to this model. Finally, the encoded message bits are embedded in those coefficients whose maximum possible changes are visually imperceptible. Experimental results show that changes resulting from the proposed method are perceptually undetectable, whereas model‐based steganography retains perceptually detectable changes. This perceptual undetectability is achieved while the perceptual quality — based on the structural similarity measure — and the security — based on two steganalysis methods — do not show any significant changes.     

Endothelial cell death, angiogenesis, and microvascular function after castration in an androgen-dependent tumor: role of vascular endothelial growth factor

The sequence of events that leads to tumor vessel regression and the functional characteristics of these vessels during hormone-ablation therapy are not known. This is because of the lack of an appropriate animal model and monitoring technology. By using in vivo microscopy and in situ molecular analysis of the androgen-dependent Shionogi carcinoma grown in severe combined immunodeficient mice, we show that castration of these mice leads to tumor regression and a concomitant decrease in vascular endothelial growth factor (VEGF) expression. Androgen withdrawal is known to induce apoptosis in Shionogi tumor cells. Surprisingly, tumor endothelial cells begin to undergo apoptosis before neoplastic cells, and rarefaction of tumor vessels precedes the decrease in tumor size. The regressing vessels begin to exhibit normal phenotype, i.e., lower diameter, tortuosity, vascular permeability, and leukocyte adhesion. Two weeks after castration, a second wave of angiogenesis and tumor growth begins with a concomitant increase in VEGF expression. Because human tumors often relapse following hormone-ablation therapy, our data suggest that these patients may benefit from combined anti-VEGF therapy.