Long-lived and unstable modes of Brownian suspensions in microchannels

We investigate the stability of the pressure-driven, low-Reynolds flow of Brownian suspensions with spherical particles in microchannels. We find two general families of stable/unstable modes: (i) degenerate modes with symmetric and anti-symmetric patterns; (ii) single modes that are either symmetric or anti-symmetric. The concentration profiles of degenerate modes have strong peaks near the channel walls, while single modes diminish there. Once excited, both families would be detectable through high-speed imaging. We find that unstable modes occur in concentrated suspensions whose velocity profiles are sufficiently flattened near the channel centreline. The patterns of growing unstable modes suggest that they are triggered due to Brownian migration of particles between the central bulk that moves with an almost constant velocity, and highly-sheared low-velocity region near the wall. Modes are amplified because shear-induced diffusion cannot efficiently disperse particles from the cavities of the perturbed velocity field.Comment: 11 pages, accepted for publication in Journal of Fluid Mechanic

Simulated Evaluation of Tooth Fracture Resistance during Instrumentation with Single-and Multi-file Rotary Systems

Introduction: Use of rotary files in root canal preparation is inevitable due to their high speed and reduced duration of treatment. However, microcracks and even root fracture may sometimes occur in teeth where canal(s) is/are prepared using these devices. The purpose of the current study was to compare NeoNiti single-file with RaCe multi-file rotary systems. Materials and Methods: An accurate scanner designed detailed three-dimensional file models, and a simulated model was developed using canal-specific features; including dentin thickness, root canal length, taper rate and root canal curvature. Cleaning and shaping conditions were simulated with appropriate speed and crack conditions for both types of files on the computer. Strain accumulation sites in the root dentin wall where microcracks was likely to occur were simulated and investigated. Abaqus and ANSYS software were used to perform finite element simulations. Results: RaCe files with 0.04 taper caused the lowest level of stress (34.33 MPa) to the simulated canal. Conversely, the highest level of stress (62.35 MPa) was applied by 8% NeoNiti file to the simulated canal. Conclusions: Based on the present experimental study, it can be concluded that RaCe multi-file rotary system may better be used in endodontic therapy, and the risk of microcracks in the tooth wall is less than that of NeoNiti single-file rotary system

Drug utilization evaluation of Rivaroxaban in both inpatient and outpatient settings: Using standard guidelines

Stroke-related atrial fibrillation (AF), deep vein thrombosis (DVT), and pulmonary thromboembolism (PE) are among the most common thromboembolic events. recently, direct oral anticoagulants (DOACs) have been slowly replacing warfarin. Rivaroxaban is a DOAC frequently prescribes to control thrombotic events. The safety and efficacy of Rivaroxaban are dependent on appropriate prescription, dosage, and other factors. This study is aimed to evaluate the Rivaroxaban utilization based on the standard protocol in both inpatient and outpatient settings. This cross-sectional/observational study was conducted for six months from 1st August 2018 to 1st February 2019 at a private hospital and also an outpatient clinic in Shiraz, Iran. First, a clinical pharmacist defined a standard protocol for Rivaroxaban utilization and several indexes (9 indexes for Non-valvular AF (NVAF) patients and 10 indexes for DVT/PE patients). Second, participants were classified into three groups (NVAF inpatients, NVAF outpatients, and DVT/PE patients). Finally, the adherence of Rivaroxaban utilization indexes in each group to was evaluated accordingly. Two hundred and forty one eligible patients were recruited into this study. Most patients (N=208), were NVAF. Rivaroxaban utilization was appropriate in 71.9%, 65.8%, and 50.6% of patients within groups 1, 2, and 3, respectively. Although medication interaction, administration regarding time/meal, and dose adjustment based on renal function showed the lowest compliance, the monitoring laboratory data and considering the underlying disorders were completely matched with the protocol. This study showed some critical errors in both settings, especially in DVT/PE patients (49.4% no match). Hence, the most productive collaboration must be developed between clinical pharmacists and clinical practitioners

The molecular biology and therapeutic potential of Nrf2 in leukemia

NF-E2-related factor 2 (Nrf2) transcription factor has contradictory roles in cancer, which can act as a tumor suppressor or a proto-oncogene in different cell conditions (depending on the cell type and the conditions of the cell environment). Nrf2 pathway regulates several cellular processes, including signaling, energy metabolism, autophagy, inflammation, redox homeostasis, and antioxidant regulation. As a result, it plays a crucial role in cell survival. Conversely, Nrf2 protects cancerous cells from apoptosis and increases proliferation, angiogenesis, and metastasis. It promotes resistance to chemotherapy and radiotherapy in various solid tumors and hematological malignancies, so we want to elucidate the role of Nrf2 in cancer and the positive point of its targeting. Also, in the past few years, many studies have shown that Nrf2 protects cancer cells, especially leukemic cells, from the effects of chemotherapeutic drugs. The present paper summarizes these studies to scrutinize whether targeting Nrf2 combined with chemotherapy would be a therapeutic approach for leukemia treatment. Also, we discussed how Nrf2 and NF-κB work together to control the cellular redox pathway. The role of these two factors in inflammation (antagonistic) and leukemia (synergistic) is also summarized

Normal oscillatory modes of rotating orthotropic disks

Knowlegde on wave and oscillations theoryRadial eigenfunctions and mode shapes for rotating isotropic and orthotropic disks. The ratio of the outer radius to the inner radius of the disk is 10Componente Curricular::Educação Superior::Ciências Exatas e da Terra::Físic