High-performance and Scalable Software-based NVMe Virtualization Mechanism with I/O Queues Passthrough

NVMe(Non-Volatile Memory Express) is an industry standard for solid-state drives (SSDs) that has been widely adopted in data centers. NVMe virtualization is crucial in cloud computing as it allows for virtualized NVMe devices to be used by virtual machines (VMs), thereby improving the utilization of storage resources. However, traditional software-based solutions have flexibility benefits but often come at the cost of performance degradation or high CPU overhead. On the other hand, hardware-assisted solutions offer high performance and low CPU usage, but their adoption is often limited by the need for special hardware support or the requirement for new hardware development. In this paper, we propose LightIOV, a novel software-based NVMe virtualization mechanism that achieves high performance and scalability without consuming valuable CPU resources and without requiring special hardware support. LightIOV can support thousands of VMs on each server. The key idea behind LightIOV is NVMe hardware I/O queues passthrough, which enables VMs to directly access I/O queues of NVMe devices, thus eliminating virtualization overhead and providing near-native performance. Results from our experiments show that LightIOV can provide comparable performance to VFIO, with an IOPS of 97.6%-100.2% of VFIO. Furthermore, in high-density VMs environments, LightIOV achieves 31.4% lower latency than SPDK-Vhost when running 200 VMs, and an improvement of 27.1% in OPS performance in real-world applications

The major causes and risk factors of total and cause-specific mortality during 5.4-year follow-up: the Shanghai Changfeng Study

To investigate the major causes and predictive factors of death in a middle-aged and elderly Chinese population. A total of 6591 residents aged ≥ 45 years from Shanghai Changfeng community were followed up for an average of 5.4 years. The causes of death were coded according to the 10th Revision of International Classification of Diseases. The mortality rate was calculated by person-years of follow up and age-standardized according to the 2010 Chinese census data. Multivariable-adjusted Cox proportional hazards model was performed to investigate the predictors of all-cause and cause-specific mortality. During the total follow-up of 35,739 person-years, 370 deaths were documented (157 from malignant neoplasms, 70 from heart diseases, 68 from cerebrovascular diseases, 75 from other causes). The age-standardized all-cause mortality rate was 798.2 per 100,000 person-years (927.9 among men and 716.7 among women). Results from multivariable analyses showed that aging, diabetes, and osteoporosis at baseline were independent predictors of all-cause mortality, with hazard ratios (HR) of 1.11 (95% CI 1.10–1.13), 1.91 (1.51–2.42), and 1.71 (1.24–2.35), respectively. The population attributable risk percent of diabetes and osteoporosis was 19.7% and 11.7%, respectively. Cigarette smoking was associated with a higher risk of all-cause mortality in men (HR and 95%CI 1.44, 1.01–2.06). In women, diabetes and osteoporosis were related to a higher risk of cardiovascular mortality (3.27, 1.82–5.88 and 1.89, 1.04–3.46, respectively). While in men, osteoporosis was related to a higher risk of malignant neoplasms mortality (2.39, 1.07–5.33). Malignant neoplasms, heart diseases, and cerebrovascular diseases are the leading causes of death. Aging, smoking, underweight, diabetes, and osteoporosis are independent predictors of premature death among middle-aged and elderly Chinese community population. Moreover, there may have been some differences in the causes and predictors of premature death between men and women

PEGylated Paclitaxel Nanomedicine Meets 3D Confinement: Cytotoxicity and Cell Behaviors

Investigating the effect of nanomedicines on cancer cell behavior in three-dimensional (3D) platforms is beneficial for evaluating and developing novel antitumor nanomedicines in vitro. While the cytotoxicity of nanomedicines on cancer cells has been widely studied on two-dimensional flat surfaces, there is little work using 3D confinement to assess their effects. This study aims to address this gap by applying PEGylated paclitaxel nanoparticles (PEG-PTX NPs) for the first time to treat nasopharyngeal carcinoma (NPC43) cells in 3D confinement consisting of microwells with different sizes and a glass cover. The cytotoxicity of the small molecule drug paclitaxel (PTX) and PEG-PTX NPs was studied in microwells with sizes of 50 × 50, 100 × 100, and 150 × 150 μm2 both with and without a concealed top cover. The impact of microwell confinement with varying sizes and concealment on the cytotoxicity of PTX and PEG-PTX NPs was analyzed by assessing NPC43 cell viability, migration speed, and cell morphology following treatment. Overall, microwell isolation was found to suppress drug cytotoxicity, and differences were observed in the time-dependent effects of PTX and PEG-PTX NPs on NPC43 cells in isolated and concealed microenvironments. These results not only demonstrate the effect of 3D confinement on nanomedicine cytotoxicity and cell behaviors but also provide a novel method to screen anticancer drugs and evaluate cell behaviors in vitro

Formation Mechanism of Multilayered Structure on Surface of Bioactive Borosilicate Glass

A conversion process of a bioactive borosilicate glass to a multilayered structure in aqueous phosphate solution was described. Microstructure, morphology and composition of the reaction product were studied using XRD, SEM and EDS analysis. It was shown that a multilayered structure, consisting of alternating hydroxyapatite (HA) and amorphous SiO2 layers, was formed on the surface of the borosilicate glass. The formation mechanism of the multilayered microstructure was also suggested. Compared with previous work, it was indicated that conversion kinetics and microstructure development of conversion products mainly depended on the composition of the bioactive glass and the concentration of phosphate solution

Chemical solution deposition of LaMnO3 buffer layers for coated conductors

Chemical solution deposition (CSD) is used to prepare LaMnO3 (LMO) buffer layers on different substrates. The results show that biaxially oriented LMO films can be successfully prepared on single-crystal SrTiO3 (STO) and STO buffered single-crystal LaAlO3 substrates when humid 4%H-2-N-2 annealing atmosphere is used. The orientation of LMO-Ni is (110)-oriented even when the annealing atmosphere is humid 4%H-2-N-2. When CSD-derived STO-Ni is used as a template, biaxially oriented LMO buffer layers with c-axis orientation can be successfully prepared. The results provide an effective route to prepare LMO-based buffer layers using CSD

Label-free colorimetric sensor for ultrasensitive detection of heparin based on color quenching of gold nanorods by graphene oxide

A novel label-free colorimetric strategy was developed for ultrasensitive detection of heparin by using the super color quenching capacity of graphene oxide (GO). Hexadecyltrimethylammonium bromide (CTAB)-stabilized gold nanorods (AuNRs) could easily self-assembly onto the surface of GO through electrostatic interaction, resulting in decrease of the surface plasmon resonance (SPR) absorption and consequent color quenching change of the AuNRs from deep to light. Polycationic protamine was used as a medium for disturbing the electrostatic interaction between AuNRs and GO. The AuNRs were prevented from being adsorbed onto the surface of GO because of the stronger interaction between protamine and GO, showing a native color of the AuNRs. On the contrary, in the presence of heparin, which was more easily to combine with protamine, the AuNRs could self-assembly onto the surface of GO, resulting in the native color disappearing of AuNRs. As the concentration of heparin increased, the color of AuNRs would gradually fade until almost colorless. The amounts of self-assembly AuNRs were proportional to the concentration of heparin, and thereby the changes in the SPR absorption and color had been used to monitor heparin levels. Under optimized conditions, good linearity was obtained in a range of 0.02-0.28 mu g/mL (R = 0.9957), and a limit of detection was 5 ng/mL. The simultaneous possession of high sensitivity and selectivity, simplicity, rapidity, and visualization enabled this sensor to be potentially applicable for ultrasensitive and rapid on-site detection toward trace heparin.A novel label-free colorimetric strategy was developed for ultrasensitive detection of heparin by using the super color quenching capacity of graphene oxide (GO). Hexadecyltrimethylammonium bromide (CTAB)-stabilized gold nanorods (AuNRs) could easily self-assembly onto the surface of GO through electrostatic interaction, resulting in decrease of the surface plasmon resonance (SPR) absorption and consequent color quenching change of the AuNRs from deep to light. Polycationic protamine was used as a medium for disturbing the electrostatic interaction between AuNRs and GO. The AuNRs were prevented from being adsorbed onto the surface of GO because of the stronger interaction between protamine and GO, showing a native color of the AuNRs. On the contrary, in the presence of heparin, which was more easily to combine with protamine, the AuNRs could self-assembly onto the surface of GO, resulting in the native color disappearing of AuNRs. As the concentration of heparin increased, the color of AuNRs would gradually fade until almost colorless. The amounts of self-assembly AuNRs were proportional to the concentration of heparin, and thereby the changes in the SPR absorption and color had been used to monitor heparin levels. Under optimized conditions, good linearity was obtained in a range of 0.02-0.28 mu g/mL (R = 0.9957), and a limit of detection was 5 ng/mL. The simultaneous possession of high sensitivity and selectivity, simplicity, rapidity, and visualization enabled this sensor to be potentially applicable for ultrasensitive and rapid on-site detection toward trace heparin. (c) 2012 Elsevier B.V. All rights reserved