Ion Doping Effects on the Lattice Distortion and Interlayer Mismatch of Aurivillius-Type Bismuth Titanate Compounds

Taking Bismuth Titanate (Bi4Ti3O12) as a Aurivillius-type compound with m = 3 for example, the ion (W6+/Cr3+) doping effect on the lattice distortion and interlayer mismatch of Bi4Ti3O12 structure were investigated by stress analysis, based on an elastic model. Since oxygen-octahedron rotates in the ab-plane, and inclines away from the c-axis, a lattice model for describing the status change of oxygen-octahedron was built according to the substituting mechanism of W6+/Cr3+ for Ti4+, which was used to investigate the variation of orthorhombic distortion degree (a/b) of Bi4Ti3O12 with the doping content. The analysis shows that the incorporation of W6+/Cr3+ into Bi4Ti3O12 tends to relieve the distortion of pseudo-perovskite layer, which also helps it to become more stiff. Since the bismuth-oxide layer expands while the pseudo-perovskite layer tightens, an analytic model for the plane stress distribution in the crystal lattice of Bi4Ti3O12 was developed from the constitutive relationship of alternating layer structure. The calculations reveal that the structural mismatch of Bi4Ti3O12 is constrained in the ab-plane of a unit cell, since both the interlayer mismatch degree and the total strain energy vary with the doping content in a similar trend to the lattice parameters of ab-plane

virtual machine replay update: improved implementation for modern hardware architecture

This paper describes a successive and updated work of Revirt project which presents a virtual machine replay framework on Xen hypervisor. As both the commodity hardware and Xen hypervisor have been changed significantly since the first publication of Revirt, the initial implementation does not meet the needs of modern architecture any more. This paper presents an improved implementation of virtual machine execution replay system called CASMotion. CASMotion has three contributions. First, CASMotion uses the performance monitor of Intel Core2 processor to construct time point of recorded events, which makes the event record more complete and precise. Second, CASMotion can fully support multi-core hardware platform which is prevalent today. Third, CASMotion is developed with more general architecture design, which makes it deployable on upstream Xen hypervisor and Dom0. Our experiments under a varity of workloads shows CASMotion has low performance impact on monitored DomU. The growth of record log is also in acceptable range. Index Terms-Revirt, execution replay, determinism, virtual machines, Xen. © 2012 IEEE.IEEE Reliability SocietyThis paper describes a successive and updated work of Revirt project which presents a virtual machine replay framework on Xen hypervisor. As both the commodity hardware and Xen hypervisor have been changed significantly since the first publication of Revirt, the initial implementation does not meet the needs of modern architecture any more. This paper presents an improved implementation of virtual machine execution replay system called CASMotion. CASMotion has three contributions. First, CASMotion uses the performance monitor of Intel Core2 processor to construct time point of recorded events, which makes the event record more complete and precise. Second, CASMotion can fully support multi-core hardware platform which is prevalent today. Third, CASMotion is developed with more general architecture design, which makes it deployable on upstream Xen hypervisor and Dom0. Our experiments under a varity of workloads shows CASMotion has low performance impact on monitored DomU. The growth of record log is also in acceptable range. Index Terms-Revirt, execution replay, determinism, virtual machines, Xen. © 2012 IEEE

Systemic threats to hypervisor non-control data

Hypervisors are becoming a widespread virtualisation layer in current computer systems. Recent successful attacks against hypervisors indicate that they face the similar integrity threats as traditional operating systems. Current approaches that secure hypervisors mainly focus on code or control-data integrity, without paying attention to non-control data integrity. In this study the authors construct attacks that target hypervisor non-control data to demonstrate which types of data within the Xen hypervisor are critical to system security. It shows privilege, resource utilisation and security policy related data are vulnerable to return-oriented programming or DMA attacks. By modifying their values from one to another, the whole system's performance will be affected. By discussing current approaches that secure hypervisors, which are not suitable for non-control data, the work is to motivate new innovation in this area to protect them.Hypervisors are becoming a widespread virtualisation layer in current computer systems. Recent successful attacks against hypervisors indicate that they face the similar integrity threats as traditional operating systems. Current approaches that secure hypervisors mainly focus on code or control-data integrity, without paying attention to non-control data integrity. In this study the authors construct attacks that target hypervisor non-control data to demonstrate which types of data within the Xen hypervisor are critical to system security. It shows privilege, resource utilisation and security policy related data are vulnerable to return-oriented programming or DMA attacks. By modifying their values from one to another, the whole system's performance will be affected. By discussing current approaches that secure hypervisors, which are not suitable for non-control data, the work is to motivate new innovation in this area to protect them

Increased miR-25 expression in serum of gastric cancer patients is correlated with CA19-9 and acts as a potential diagnostic biomarker

To evaluate miR-25 expression in serum of gastric cancer (GC) patients and whether it can be a potential biomarker for GC diagnosis

deterministic replay of multithread applications using virtual machine

The deterministic replay technology usually is used to reproduce non-deterministic failures, especially the concurrency failures which are hard to debug with cyclic-debugging techniques. Previous techniques either incur large overhead or require custom hardware extensions. They have also suffered from the interference with irrelevant processes. This paper introduces WDRVirt, a new software based replay system that provides deterministic replay for concurrent applications. This paper makes three contributions. First, WDRVirt enforces a deterministic replay for the interleaving of lock acquisitions with low performance overhead. Second, different from the previous works, we customize the lightweight virtual machine execution environment as the container for the target program. WDRVirt replays the container to avoid the interference with other irrelevant processes. At last, WDRVirt is deployed into both virtual machine(VM) and virtual machine manager(VMM) to deal with different types of non-deterministic event. We have implemented this system based on the Xen virtualization platform. Our experiments with real-world benchmarks demonstrate the effectiveness of WDRVirt. © 2012 IEEE.IEEE Comput. Soc. Tech. Comm. Distrib. Process.The deterministic replay technology usually is used to reproduce non-deterministic failures, especially the concurrency failures which are hard to debug with cyclic-debugging techniques. Previous techniques either incur large overhead or require custom hardware extensions. They have also suffered from the interference with irrelevant processes. This paper introduces WDRVirt, a new software based replay system that provides deterministic replay for concurrent applications. This paper makes three contributions. First, WDRVirt enforces a deterministic replay for the interleaving of lock acquisitions with low performance overhead. Second, different from the previous works, we customize the lightweight virtual machine execution environment as the container for the target program. WDRVirt replays the container to avoid the interference with other irrelevant processes. At last, WDRVirt is deployed into both virtual machine(VM) and virtual machine manager(VMM) to deal with different types of non-deterministic event. We have implemented this system based on the Xen virtualization platform. Our experiments with real-world benchmarks demonstrate the effectiveness of WDRVirt. © 2012 IEEE

Overwintering and Yield Responses of Two Late-Summer Seeded Alfalfa Cultivars to Phosphate Supply

Phosphorus (P) is one of the essential nutrients for alfalfa (Medicago sativa L.) growth, but P deficiency in soil is a common phenomenon. Applying an appropriate amount of P fertilizer for alfalfa in the establishment year improves winter survival, helps achieve sustainable high yields, and promotes the best economic returns. The objective of this study was to determine the effect of different P fertilization rates (0, 22, 44, and 66 kg P ha−1) on winter survival, forage yield, and root traits of two late-summer seeded alfalfa cultivars (dormant and semi-dormant) in the establishment and first production year. Our results showed that applying an appropriate amount of P fertilizer can increase forage yield and enhance the persistence of late-summer seeded alfalfa by promoting the development of crown and root traits and improving winter survival, especially for semi-dormant cultivars. Late-summer seeding and application of appropriate P fertilizer rates are effective agronomic methods for alfalfa in cold and arid winter regions, and can be used as strategies to improve fertility and stabilize soil from wind erosion for sustainable agriculture. To obtain high rate of survival in winter, the optimal P fertilization rates for the dormant and semi-dormant alfalfa cultivars in this study were 31.4 and 41.3 kg P ha−1, whereas the optimum P application rates for high forage yields were 31.3 and 31.5 kg P ha−1, respectively

Overwintering and Yield Responses of Two Late-Summer Seeded Alfalfa Cultivars to Phosphate Supply

Phosphorus (P) is one of the essential nutrients for alfalfa (Medicago sativa L.) growth, but P deficiency in soil is a common phenomenon. Applying an appropriate amount of P fertilizer for alfalfa in the establishment year improves winter survival, helps achieve sustainable high yields, and promotes the best economic returns. The objective of this study was to determine the effect of different P fertilization rates (0, 22, 44, and 66 kg P ha−1) on winter survival, forage yield, and root traits of two late-summer seeded alfalfa cultivars (dormant and semi-dormant) in the establishment and first production year. Our results showed that applying an appropriate amount of P fertilizer can increase forage yield and enhance the persistence of late-summer seeded alfalfa by promoting the development of crown and root traits and improving winter survival, especially for semi-dormant cultivars. Late-summer seeding and application of appropriate P fertilizer rates are effective agronomic methods for alfalfa in cold and arid winter regions, and can be used as strategies to improve fertility and stabilize soil from wind erosion for sustainable agriculture. To obtain high rate of survival in winter, the optimal P fertilization rates for the dormant and semi-dormant alfalfa cultivars in this study were 31.4 and 41.3 kg P ha−1, whereas the optimum P application rates for high forage yields were 31.3 and 31.5 kg P ha−1, respectively

Combined inhibition of epidermal growth factor receptor and cyclooxygenase-2 leads to greater anti-tumor activity of docetaxel in advanced prostate cancer.

The epidermal growth factor receptor (EGFR) and cyclooxygenase-2(COX-2) play a critical role in disease progression, relapse and therapeutic resistance of advanced prostate cancer (PCa). In this paper, we evaluated, for the first time, the therapeutic benefit of blocking EGRF and/or COX-2 (using gefitinib and NS-398, respectively) in terms of improving the efficacy of the conventional clinical chemotherapeutic drug docetaxel in vitro and vivo. We showed that EGFR and COX-2 expression was higher in metastatic than non-metastatic PCa tissues and cells. Docetaxel, alone or in combination with gefitinib or NS-398, resulted in a small decrease in cell viability. The three drug combination decreased cell viability to a greater extent than docetaxel alone or in combination with gefitinib or NS-398. Docetaxel resulted in a modest increase in apoptotic cell in metastatic and non-metastatic cell lines. NS-398 markedly enhanced docetaxel-induced cell apoptosis. The combination of the three drugs caused even more marked apoptosis and resulted in greater suppression of invasive potential than docetaxel alone or in association with gefitinib or NS-398. The combination of all three drugs also resulted in a more marked decrease in NF-ΚB, MMP-9 and VEGF levels in PC-3M cells. These in vitro findings were supported by in vivo studies showing that docetaxel in combination with gefitinib and NS-398 was significantly more effective than any individual agent. Based on previous preclinical research, we conclude that simultaneously blocking EGFR and COX-2 by gefitinib and NS-398 sensitizes advanced PCa cells to docetaxel-induced cytotoxicity

Indentation Behavior and Mechanical Properties of Tungsten/Chromium co-Doped Bismuth Titanate Ceramics Sintered at Different Temperatures

A sort of tungsten/chromium(W/Cr) co-doped bismuth titanate (BIT) ceramics (Bi4Ti2.95W0.05O12.05 + 0.2 wt % Cr2O3, abbreviate to BTWC) are ordinarily sintered between 1050 and 1150 °C, and the indentation behavior and mechanical properties of ceramics sintered at different temperatures have been investigated by both nanoindentation and microindentation technology. Firstly, more or less Bi2Ti2O7 grains as the second phase were found in BTWC ceramics, and the grain size of ceramics increased with increase of sintering temperatures. A nanoindentation test for BTWC ceramics reveals that the testing hardness of ceramics decreased with increase of sintering temperatures, which could be explained by the Hall–Petch equation, and the true hardness could be calculated according to the pressure-state-response (PSR) model considering the indentation size effect, where the value of hardness depends on the magnitude of load. While, under the application of microsized Vickers, the sample sintered at a lower temperature (1050 °C) gained four linearly propagating cracks, however, they were observed to shorten in the sample sintered at a higher temperature (1125 °C). Moreover, both the crack deflection and the crack branching existed in the latter. The hardness and the fracture toughness of BTWC ceramics presented a contrary variational tendency with increase of sintering temperatures. A high sintering tends to get a lower hardness and a higher fracture toughness, which could be attributed to the easier plastic deformation and the stronger crack inhibition of coarse grains, respectively, as well as the toughening effect coming from the second phase