Strategic Learning for Active, Adaptive, and Autonomous Cyber Defense

The increasing instances of advanced attacks call for a new defense paradigm that is active, autonomous, and adaptive, named as the \texttt{`3A'} defense paradigm. This chapter introduces three defense schemes that actively interact with attackers to increase the attack cost and gather threat information, i.e., defensive deception for detection and counter-deception, feedback-driven Moving Target Defense (MTD), and adaptive honeypot engagement. Due to the cyber deception, external noise, and the absent knowledge of the other players' behaviors and goals, these schemes possess three progressive levels of information restrictions, i.e., from the parameter uncertainty, the payoff uncertainty, to the environmental uncertainty. To estimate the unknown and reduce uncertainty, we adopt three different strategic learning schemes that fit the associated information restrictions. All three learning schemes share the same feedback structure of sensation, estimation, and actions so that the most rewarding policies get reinforced and converge to the optimal ones in autonomous and adaptive fashions. This work aims to shed lights on proactive defense strategies, lay a solid foundation for strategic learning under incomplete information, and quantify the tradeoff between the security and costs.Comment: arXiv admin note: text overlap with arXiv:1906.1218

Adamantane-Modified Graphene Oxide for Cyanate Ester Resin Composites with Improved Properties

The conjugation of graphene and polymers has attracted great attention for the fabrication of functional hybrid nanomaterials. Here, we demonstrate the modification of graphene oxide (GO) with adamantane (AMT) through the diimide-activated amidation reaction. The modification of GO with AMT improves the dispersion and decreases the interfacial polarization of GO, causing a lower dielectric constant for the fabricated GO/AMT hybrid materials. The structures of GO/AMT were studied by Fourier transform infrared spectroscopy and Raman spectroscopy. Furthermore, the mechanical properties, thermal stability, and dielectric constant of GO/AMT composites were measured at a low cured temperature using various techniques, such as differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical thermal analysis. It was found that the synthesized GO/AMT materials with different contents were blended into cyanate ester (CE) resins, resulting in a lower cure temperature, smaller dielectric constant, higher thermal stability, and stronger water resistance. It is expected that this novel GO/AMT-CE material will have potential applications for replacing traditional thermosetting resins

Mining natural products related to paclitaxel reveals the possible biosynthetic pathway of paclitaxel

Paclitaxel is a widely used anti-tumor drug. Currently, paclitaxel can only be extracted from plants or synthesized by chemical semi-synthesis, which cause environmental damage and cannot meet the growing demand. However, the complete biosynthetic pathway of paclitaxel is still not clear, which greatly limits the production of paclitaxel using methods such as synthetic biology. Here, we deduced the paclitaxel biosynthetic pathway by searching all possible intermediates in the paclitaxel synthesis pathway from the natural product databases. In addition, we performed the transcriptome sequencing of Taxus brevifolia and performed co-expression analysis of the identified genes in the paclitaxel synthesis pathway. All these results laid a solid foundation for the elucidation of paclitaxel biosynthetic pathway

A rigid microfluidic chip for high-throughput fluorescence-activated cell sorting

Fluorescence-activated cell sorting (FACS) holds great promise for the separation of single cells or cell populations according to specific light scattering and fluorescent characteristics. Here, we present a new perspective on microfluidic FACS (μFACS) with predictable geometry, which meets the requirements of high-throughput analysis and sorting. Instead of the widely applied elastic polydimethylsiloxane (PDMS), a rigid epoxy resin chip was rapidly fabricated and irreversibly encapsulated to eliminate channel deformation (tenfold reduction) and enhance performance while meeting high pressure (>600 kPa) and high flow rate application scenarios. Fluorescence discrimination and particle differentiation were additionally validated in a self-contained μFACS system using calibration microspheres and mammalian cells. The μFACS chip and system were integrally optimized to achieve a minimum interval (0.58 ms) with a mean flow rate of 1.5 m/s. Ultimately, event recording and automated sorting were accomplished in real time while achieving a sorting efficiency of 87% at cell throughput of 8,000 events/s. This rigid chip for high-throughput μFACS, which is independent of the physical properties of cells could pave the way for cell screening in plasma samples for personalized medicine

Mining natural products related to paclitaxel reveals the possible biosynthetic pathway of paclitaxel

Paclitaxel is a widely used anti-tumor drug. Currently, paclitaxel can only be extracted from plants or synthesized by chemical semi-synthesis, which cause environmental damage and cannot meet the growing demand. However, the complete biosynthetic pathway of paclitaxel is still not clear, which greatly limits the production of paclitaxel using methods such as synthetic biology. Here, we deduced the paclitaxel biosynthetic pathway by searching all possible intermediates in the paclitaxel synthesis pathway from the natural product databases. In addition, we performed the transcriptome sequencing of Taxus brevifolia and performed co-expression analysis of the identified genes in the paclitaxel synthesis pathway. All these results laid a solid foundation for the elucidation of paclitaxel biosynthetic pathway

Additional file 1 of Escitalopram versus other antidepressive agents for major depressive disorder: a systematic review and meta-analysis

Additional file 1: Figure S1. Risk of bias summary. Figure S2. Failure to respond (at 1-4 weeks): Escitalopram versus other SSRIs. Figure S3. Failure to respond (at 1-4 weeks): Escitalopram versus newer ADs. Figure S4. Failure to respond (at 16-24 weeks): Escitalopram versus other SSRIs. Figure S5. Failure to respond (at 16-24 weeks): Escitalopram versus newer ADs. Figure S6. Failure to remission at endpoint (6-12 weeks): Escitalopram versus newer ADs. Figure S7. Failure to remission (at 16-24 weeks): Escitalopram versus other SSRIs. Figure S8. Failure to remission (at 16-24 weeks): Escitalopram versus newer ADs. Figure S9. Standardized mean difference at endpoint (6-12 weeks): Escitalopram versus other SSRIs. Figure S10. Standardized mean difference at endpoint (6-12 weeks): Escitalopram versus newer ADs. Figure S11. Subjects with at least one TEAE: Escitalopram versus newer ADs. Figure S12. Excluding trials whose dropout rate was greater than 20%: Escitalopram versus other SSRIs (dropout rate greater than 20% in both arms). Figure S13. Excluding trials whose dropout rate was greater than 20%: Escitalopram versus other SSRIs (dropout rate greater than 20% in only one arm). Figure S14. Funnel plot of comparison: Failure to respond at endpoint (6-12 weeks): Escitalopram versus other SSRIs

The investigation of structure and IR spectra for hydrated potassium ion clusters K

The hydration of K+(H2O)n has been widely studied and believe to be important for understanding solvent properties in biological and chemical systems. However, understanding the structure and the spectrum information K+(H2O)n with changing n is limited. Here, we investigated the clusters K+(H2O)n=1–16 and further studied the IR spectrums of the most stable clusters with density functional theory. The configuration, bond length, vibration frequency were given out. It shows that K+(H2O)8(H2O)n, a distorted square antiprism in inner layer, is the main configuration with hydration distance rK - OI 0.296 nm when the hydration number n is bigger than 8. The saturated hydration number is 8 in the first hydration layer and the water molecules of the second hydration sphere have little effect on the inner ones when n> 8. A detailed classification about the hydrated water molecules was made according to the role of acceptor or donor hydrogen bonding in clusters. The vibration frequency of the different kinds of water molecules were also detailly identified. The results are valuable for further determination of the K+(H2O)n clusters in aqueous solutions