A Cost-effective Shuffling Method against DDoS Attacks using Moving Target Defense

Moving Target Defense (MTD) has emerged as a newcomer into the asymmetric field of attack and defense, and shuffling-based MTD has been regarded as one of the most effective ways to mitigate DDoS attacks. However, previous work does not acknowledge that frequent shuffles would significantly intensify the overhead. MTD requires a quantitative measure to compare the cost and effectiveness of available adaptations and explore the best trade-off between them. In this paper, therefore, we propose a new cost-effective shuffling method against DDoS attacks using MTD. By exploiting Multi-Objective Markov Decision Processes to model the interaction between the attacker and the defender, and designing a cost-effective shuffling algorithm, we study the best trade-off between the effectiveness and cost of shuffling in a given shuffling scenario. Finally, simulation and experimentation on an experimental software defined network (SDN) indicate that our approach imposes an acceptable shuffling overload and is effective in mitigating DDoS attacks

Deformation and failure mechanisms of electrochemically lithiated silicon thin films

A fundamental understanding of mechanical behavior of a Li–Si system is necessary to address the poor mechanical integrity of amorphous silicon (a-Si) electrodes, in order to utilize their enormous capacity in Li-ion batteries. In this work, deformation and failure mechanisms of electrochemically lithiated a-Si thin films were investigated using nanoindentation and molecular dynamics simulation techniques. The cracking observed in the a-Si thin films after the initial lithiation–delithiation cycle is associated with the tension stress developed when constrained by the substrates. The MD simulations provide an atomistic insight on the origin of plasticity and transition of fracture mechanisms with increasing lithium concentration in the electrode. Both experiment and the MD simulations indicate reduced strength, elastic modulus but increased ductility in the a-Si films after the full lithiation–delithiation cycle, as a result of increased disorder in the microstructures. Also, the mapping of void nucleation and growth indicates different failure modes in pristine and delithiated a-Si

Patient, staff empowerment and hand hygiene bundle improved and sustained hand hygiene in hospital wards

AIM: We piloted a hand hygiene (HH) project in a ward, focusing on World Health Organization moments 1 and 4. Our aim was to design highly reliable interventions to achieve &gt;90% compliance.METHODS: Baseline HH compliance was 57 and 67% for moments 1, 4, respectively, in 2015. After the pilot ward showed sustained improvement, we launched the 'HH bundle' throughout the hospital. This included: (i) appointment of HH champions; (ii) verbal/visual bedside reminders; (iii) patient empowerment; (iv) hand moisturisers; (v) tagging near-empty handrub (HR) bottles. Other hospital-wide initiatives included: (vi) Smartphone application for auditing; (vii) 'Speak up for Patient Safety' Campaign in 2017 for staff empowerment; (viii) making HH a key performance indicator.RESULTS: Overall HH compliance increased from a baseline median of 79.6-92.6% in end-2019. Moments 1 and 4 improved from 71 to 92.7% and from 77.6 to 93.2%, respectively. Combined HR and hand wash consumption increased from a baseline median of 82.6 ml/patient day (PD) to 109.2 mL/PD. Health-care-associated rotavirus infections decreased from a baseline median of 4.5 per 10 000 PDs to 1.5 per 10 000 PDs over time.CONCLUSIONS: The 'HH Bundle' of appointing HH champions, active reminders and feedback, patient education and empowerment, availability of hand moisturisers, tagging near-empty hand rub bottles together with hospital-wide initiatives including financial incentives and the 'Speak Up for Patient Safety' campaign successfully improved the overall HH compliance to &gt;90%. These interventions were highly reliable, sustained over 4 years and also reduced health-care-associated rotavirus infection rates.</p

Polymeric Binders in Modern Metal-ion Batteries

Polymeric binders are important components in maintaining the structural integrity of electrodes in energy storage devices. The emergence of alloy- and conversion-type materials (e.g. silicon anodes and lithium–sulfur batteries) as next-generation energy storage materials has attracted notable scientific and commercial interest in binder research. This interest is significantly motivated by the critical roles of binders in addressing the fundamental issues of these emerging systems, such as the large volume change of silicon anode and the shuttling effect of lithium–sulfur batteries. Considering the inherent drawbacks of traditional polyvinylidene fluoride (PVDF) binders, it is necessary to develop binders with excellent mechanical and electrochemical properties to facilitate the next-generation battery systems. Herein, in this chapter, we review the fundamental binding theory and emerging binders in energy storage systems. Then, the binder design strategies and applications are summarized. Finally, the challenges and future opportunities of binder research are proposed

Relationship between FGFR1 Gene Regulation of Circulating Tumor Cells and Clinical Features of Non-small Cell Lung Cancer

Background and objective The methods of detection for recurrence and metastasis in patients with non-small cell lung cancer (NSCLC) have hysteresis and one-sidedness. This study summarizes the relationship between the circulating tumor cell (CTC) in peripheral blood, expression of fibroblast growth factor receptor 1 (FGFR1) and clinic pathological features in 30 patients with NSCLC so as to provide new ideas for the detection of tumor recurrence and metastasis. Methods To analyze the clinical data and CTC detection data of 30 cases of NSCLC in Department of Thoracic Surgery, Peking Union Medical College Hospital from November 2016 to June 2017. Results Data analysis showed that the positive rate of CTC in peripheral blood was remarkably correlated with the smoking history (P=0.016). There was no significant correlation among the pathological type and CTC positive rate and the expression of FGFR1 (P=0.202, P=0.806). There was no significant difference in the expression of FGFR1 in different type CTC cells (P=0.094). Conclusion The positive rate of CTC was significantly correlated with the smoking history of patients with NSCLC. There was no significant difference in CTC classification and FGFR1 expression in different pathological types of NSCLC. There was no significant difference in the expression of FGFR1 between different types of CTCs. We look forward to a larger sample size and inclusion of follow-up data to arrive at more clinically relevant conclusions about CTC and FGFR1 gene expression

The role and research progress of macrophages after heart transplantation

Since the 60s of the 20th century, heart transplantation has been the best treatment for patients with end-stage heart failure. Due to the increasing number of patients, how to expand the number of donor organs and enhance immune compatibility has become an urgent problem to be solved at this stage. Although current immunosuppression is effective, its side effects are also quite obvious, such as opportunistic infections and malignant tumors. In this review, we focus on the important role in macrophages after heart transplantation and their potential targets for achieving allogeneic graft tolerance, in order to improve effective graft survival and reduce infection and the occurrence of malignant tumors

Nanotribological properties of nanotextured Ni-Co coating surface measured with AFM colloidal probe technique

Surface-texturing is a useful method of modifying surface frictional performance. A simple, novel, easily-controlled method was used to fabricate different kinds of textures on an Ni-Co coating surface. The nanotribological properties were characterised by atomic force microscope (AFM) with a colloidal probe. The results showed that, compared to the original Ni-Co coating surface, the nanotextured surface can adjust the surface friction forces. The half-elliptic patterns have better tribological properties than hemispherical patterns. Therefore, both laser energy and laser scanning speed will influence the friction performances of Ni-Co coating surfaces

Structural transformations and stress of amorphous silicon anodes during initial lithiation cycle: A molecular dynamics study

Silicon (Si) is widely regarded as one of the most promising anode materials for Li ion battery (LIB) due to its highest known theoretical specific capacity (4200mAhg-1). Particularly, amorphous silicon has recently attracted great interest due to its robust lithiation behavior. Silicon electrodes are subjected to charge-discharge via an alloying-dealloying (lithiation-delithiation) mechanism. It enables the host silicon to store up to 4.4 lithium atoms per silicon atom, which gives more than ten times greater capacity compared with conventional graphite based electrodes. However, this enormous capacity comes with the expense of significant structural changes to the host silicon, which results in poor mechanical integrity. To address this issue, it is important to understand the transitional structural and mechanical properties of silicon during charge-discharge process. In this study, molecular dynamic simulation is employed to study the structure and mechanics of an amorphous silicon thin film (2.7nm) during a complete lithiation-delithiation cycle. The microstructure evolution during lithiation process is associated with the break of covalent amorphous structure into small clusters, when Li concentration exceeds ~Li0.25Si. Also, it is evident that Li induced stress is largely dependent on lithium concentration in silicon. Steep stress gradients were observed when the lithium content in the anode is very low (<Li0.25Si). Plastic flow and stress relaxation are dominant in higher Li concentrations. Furthermore, we show that the rate of si-si bond breaking is lithium concentration dependent. Also, the Radial Distribution Function (RDF) analysis revealed a defective amorphous structure in silicon film after a complete lithiation/delithiation cycle, which is attributed to breaking down of covalent silicon network and subsequent plastic flow. These results are useful in understanding lithiation-delithiation mechanisms of silicon and the favourable charge-discharge depths to avoid extreme stresses. Furthermore, these results are believed to be able to help improve the materials selection and design of next generation Li ion batteries

Primary Neuroendocrine Carcinoma of Thymus Caused Cushing Syndrome: Surgical Treatment and Prognosis Analysis

Background and objective Primary neuroendocrine carcinoma of thymus (pNECT) is a rare thymic neoplasm. Some pNECTs could produce an adrenocorticotropic hormone and cause Cushing syndrome (CS). The aim os this study is to discuss the diagnostic technique and surgical management of pNECT-caused CS and analyze prognosis factors to improve the clinical experience of the disease. Methods The outcome of surgery and follow-up of 14 cases (eight males and six females) of pNECT-caused CS were retrospectively analyzed from November 1987 to June 2013. Result The median age of the patients was 29, and the median duration of the disease was four months (1 month-44 months). All cases exhibited clinical evidence for the diagnosis of CS, and thoracic computed tomography (CT) was used to detect thymic tumors. Surgical treatment significantly decreased the concentration of both serum cortisol and adrenocorticotropic hormone (P<0.01) but caused one death in the perioperative period. With multidisciplinary therapy, the median survival was 38 months. Conclusion pNECT-caused CS is a rare disease with aggressive characteristics and unclear prognosis. Early diagnosis and therapy is a challenge for clinicians. Thoracic CT is important for disease location and preoperative evaluation and should be routinely applied to all CS patients to allow early surgery and improved prognosis