The effect of manganese oxide on the sinterability of hydroxyapatite

The sinterability of manganese oxide (MnO2) doped hydroxyapatite (HA) ranging from 0.05 to 1 wt% was investigated. Green samples were prepared and sintered in air at temperatures ranging from 1000 to 1400 °C. Sintered bodies were characterized to determine the phase stability, grain size, bulk density, hardness, fracture toughness and Young's modulus. XRD analysis revealed that the HA phase stability was not disrupted throughout the sintering regime employed. In general, samples containing less than 0.5 wt% MnO2 and when sintered at lower temperatures exhibited higher mechanical properties than the undoped HA. The study revealed that all the MnO2-doped HA achieved >99% relative density when sintered at 1100–1250 °C as compared to the undoped HA which could only attained highest value of 98.9% at 1150 °C. The addition of 0.05 wt% MnO2 was found to be most beneficial as the samples exhibited the highest hardness of 7.58 GPa and fracture toughness of 1.65 MPam1/2 as compared to 5.72 GPa and 1.22 MPam1/2 for the undoped HA when sintered at 1000 °C. Additionally, it was found that the MnO2-doped samples attained E values above 110 GPa when sintered at temperature as low as 1000 °C if compared to 1050 °C for the undoped HA

Local infiltration analgesia versus femoral nerve block in total knee arthroplasty: A meta-analysis

AbstractIntroductionLocal infiltration analgesia (LIA) and femoral nerve block (FNB) are both used for the pain management after total knee arthroplasty (TKA). Controversy still remains regarding the optimal technique for pain relief in patients undergoing TKA. The purpose of this meta-analysis was to compare the analgesia achieved with LIA and the one from FNB following TKA.HypothesisLIA achieves better pain control than FNB in patients with TKA.MethodsDatabases, including Pubmed, EMBASE, the Cochrane Library and Web of Science were comprehensively searched to identify studies comparing LIA with FNB for patients with TKA. Two reviewers independently selected trials, extracted data, and assessed the methodological qualities of included studies. Data were analyzed by RevMan 5.2.ResultsNine RCTs involving 782 patients were included. LIA achieved more rapid pain relief (VAS) at 6h postoperatively [SMD6h=−0.92, 95% CI (−1.38, −0.47)] than FNB. There were no significant differences at 24h and 48h [SMD24h=−0.03, 95% CI (−0.46, 0.40); SMD48h=0.28, 95% CI (−0.35, 0.91)], VAS with activity at 24h and 48h [SMD6h=−0.54, 95% CI (−1.62, 0.54); SMD24h=−0.22, 95% CI (−1.41, 0.96); SMD48h=−0.08, 95% CI (−0.52, 0.69)], opioid consumption at 24h and 48h [SMD24h=−0.24, 95% CI (−0.82, 0.34); SMD48h=0.15, 95% CI (0.25, 0.54)] and length of hospital stay [MD=−0.52, 95% CI (−1.13, 0.09)].DiscussionLIA may be the better choice in the pain management of TKA for it could achieve fast pain relief and is easier to perform than FNB for patients with TKA.Level of evidenceLevel II, meta-analysis and systematic review

Search for Intrinsic Excitations in 152Sm

The 685 keV excitation energy of the first excited 0+ state in 152Sm makes it an attractive candidate to explore expected two-phonon excitations at low energy. Multiple-step Coulomb excitation and inelastic neutron scattering studies of 152Sm are used to probe the E2 collectivity of excited 0+ states in this "soft" nucleus and the results are compared with model predictions. No candidates for two-phonon K=0+ quadrupole vibrational states are found. A 2+, K=2 state with strong E2 decay to the first excited K=0+ band and a probable 3+ band member are established.Comment: 4 pages, 6 figures, accepted for publication as a Rapid Communication in Physical Review

Network anomaly detection by using a time-decay closed frequent pattern

© 2019 by the authors. Anomaly detection of network traffic flows is a non-trivial problem in the field of network security due to the complexity of network traffic. However, most machine learning-based detection methods focus on network anomaly detection but ignore the user anomaly behavior detection. In real scenarios, the anomaly network behavior may harm the user interests. In this paper, we propose an anomaly detection model based on time-decay closed frequent patterns to address this problem. The model mines closed frequent patterns from the network traffic of each user and uses a time-decay factor to distinguish the weight of current and historical network traffic. Because of the dynamic nature of user network behavior, a detection model update strategy is provided in the anomaly detection framework. Additionally, the closed frequent patterns can provide interpretable explanations for anomalies. Experimental results show that the proposed method can detect user behavior anomaly, and the network anomaly detection performance achieved by the proposed method is similar to the state-of-the-art methods and significantly better than the baseline methods

Achieving λ/10 resolution CW STED nanoscopy with a Ti:Sapphire oscillator

In this report, a Ti:Sapphire oscillator was utilized to realize synchronization-free stimulated emission depletion (STED) microscopy. With pump power of 4.6 W and sample irradiance of 310 mW, we achieved super-resolution as high as 71 nm. With synchronization-free STED, we imaged 200 nm nanospheres as well as all three cytoskeletal elements (microtubules, intermediate filaments, and actin filaments), clearly demonstrating the resolving power of synchronization-free STED over conventional diffraction limited imaging. It also allowed us to discover that, Dylight 650, exhibits improved performance over ATTO647N, a fluorophore frequently used in STED. Furthermore, we applied synchronization-free STED to image fluorescently-labeled intracellular viral RNA granules, which otherwise cannot be differentiated by confocal microscopy. Thanks to the widely available Ti:Sapphire oscillators in multiphoton imaging system, this work suggests easier access to setup super-resolution microscope via the synchronization-free STED. © 2012 Liu et al

Spin relaxation due to random Rashba spin-orbit coupling in GaAs (110) quantum wells

We investigate the spin relaxation due to the random Rashba spin-orbit coupling in symmetric GaAs (110) quantum wells from the fully microscopic kinetic spin Bloch equation approach. All relevant scatterings, such as the electron-impurity, electron--longitudinal-optical-phonon, electron--acoustic-phonon, as well as electron-electron Coulomb scatterings are explicitly included. It is shown that our calculation reproduces the experimental data by M\"uller {\em et al.} [Phys. Rev. Lett. {\bf 101}, 206601 (2008)] for a reasonable choice of parameter values. We also predict that the temperature dependence of spin relaxation time presents a peak in the case with low impurity density, which originates from the electron-electron Coulomb scattering.Comment: 5 pages, 2 figures, EPL in pres

Self and Peer Assessment in K–12 Chinese Language Classrooms: Teachers’ Perceptions and Implementation

This is the final version. Available on open access from Van Yuzuncu Yil University via the link in this recordLittle research has been conducted on self and peer assessment (hereafter, SA and PA) in Chinese language education in the United States, despite the fact that both forms of assessment have multiple benefits for language learning and it is argued they should be an integral component of language teachers’ repertoire of classroom assessment. Particularly, little is known about Chinese language teachers’ perceptions of SA and PA and their classroom SA and PA practices. To address this knowledge gap, this study aimed at exploring Chinese language teachers’ perceptions and implementation of SA and PA and establishing a ground for future research in this field. Using a qualitative methodology, we interviewed ten K–12 Chinese language teachers in US schools. By examining the interview responses of those teachers, this study revealed some important findings. Notably, all the teachers realized the benefits of SA and PA for student learning. Yet, there was rare use of them in most teachers’ classrooms. We discussed this gap by drawing upon the probed responses of the teachers as well as our inferences. The findings of this study inform SA and PA of Chinese language in K–12 classrooms and professional development for Chinese language teachers in US schools.US Department of EducationMichigan State University (MSU), College of Educatio