A novel nano-hydroxyapatite (HA)/konjac glucomannan composite scaffold with high porosity was developed by blending nano-HA
particles with konjac glucomannan in alkaline solution. The scanning electron microscopy, porosity measurement, X-ray diffraction(XRD),
and Fourier transformed infrared(FTIR) spectroscopy were used to analyze the physical and chemical properties of the composite
scaffolds. The pure konjac glucomannan scaffolds and composite scaffolds were similar in their macroscopic morphology, however,
the microscopic morphology on porewall surfaces was quite different. The diffraction patterns of XRD revealed the presence
of konjac glucomannan and HA in the composite scaffolds. In addition, the results of FTIR also showed the existence of the
functional group of HA. These results reveal that the newly developed nano-HA/konjac glucomannan composite scaffold may serve
as a good three-dimensional substrate in bone tissue engineering. 相似文献
With the exponential growth of user-generated content, policies and guidelines are not always enforced in social media, resulting in the prevalence of deviant content violating policies and guidelines. The adverse effects of deviant content are devastating and far-reaching. However, the detection of deviant content from sparse and imbalanced textual data is challenging, as a large number of stakeholders are involved with different stands and the subtle linguistic cues are highly dependent on complex context. To address this problem, we propose a multi-view attention-based deep learning system, which combines random subspace and binary particle swarm optimization (RS-BPSO) to distill content of interest (candidates) from imbalanced data, and applies the context and view attention mechanisms in convolutional neural network (dubbed as SSCNN) for the extraction of structural and semantic features. We evaluate the proposed approach on a large-scale dataset collected from Facebook, and find that RS-BPSO is able to detect whether the content is associated with marijuana with an accuracy of 87.55%, and SSCNN outperforms baselines with an accuracy of 94.50%.
The widespread fake news in social networks is posing threats to social stability, economic development, and political democracy, etc. Numerous studies have explored the effective detection approaches of online fake news, while few works study the intrinsic propagation and cognition mechanisms of fake news. Since the development of cognitive science paves a promising way for the prevention of fake news, we present a new research area called Cognition Security (CogSec), which studies the potential impacts of fake news on human cognition, ranging from misperception, untrusted knowledge acquisition, targeted opinion/attitude formation, to biased decision making, and investigates the effective ways for fake news debunking. CogSec is a multidisciplinary research field that leverages the knowledge from social science, psychology, cognition science, neuroscience, AI and computer science. We first propose related definitions to characterize CogSec and review the literature history. We further investigate the key research challenges and techniques of CogSec, including humancontent cognition mechanism, social influence and opinion diffusion, fake news detection, and malicious bot detection. Finally, we summarize the open issues and future research directions, such as the cognition mechanism of fake news, influence maximization of fact-checking information, early detection of fake news, fast refutation of fake news, and so on. 相似文献