Uniaxial and Multiaxial Fatigue Behaviors of HDPE and Several Neat and Short Glass Fiber Reinforced Thermoplastics Including the Effects of Temperature, Mean Stress, Frequency, and Stress Concentration

High-Density Polyethyelen (HDPE) is a very high volume polymer used in many applications such as piping systems in geo-exchange systems or replacing heavier materials in automotive fuel tanks. The most common processing techniques to manufacture HDPE parts are injection molding, blow molding, and compression molding. Combination of cyclic and static loads are inevitable in many applications, therefore, this study investigated tensile, creep, fatigue, and creep-fatigue interaction of HDPE under a variety of conditions including environmental (temperature), stress concentration, cycling frequency, and stress state. Multiaxial stress state effect on fatigue life at room temperature was investigated for HDPE, Polypropylene, neat Nylon 66, and Nylon66 short fiber (%30 glass fiber) composite. The damage mechanisms in the considered thermoplastics were evaluated through experimental fatigue tests. Notch effect on fatigue life was also studied due to the importance of stress concentration effect on fatigue behavior and the fact that they are inevitable in many design situations. Current common multiaxial fatigue criteria were assessed for experimental data and a critical plane-based damage parameter was proposed for multiaxial behavior of HDPE as well as the other studied thermoplastics. Injection molding as a common processing technique for polymers has a high production rate, low manufacturing cost, and flexibility to manufacture complex geometries. Experimental multiaxial fatigue data from literature for injection molded short glass fiber reinforced thermoplastics including Polypropylene, Polybutylene Terephthalate, and Nylon 66 were also included in this study to investigate the effect of fiber orientation on multiaxial fatigue behavior of these polymeric composites with aligned fibers. A modification of the critical plane damage parameter was proposed to account for fiber orientation, mean stress, and stress concentration on multiaxial fatigue behavior of short glass fiber reinforced thermoplastics with injection molding processing techniqu

Spectrofluorimetric Determination of Human Serum Albumin Using Terbium-Danofloxacin Probe

A spectrofluorimetric method is proposed for the determination of human serum albumin (HSA) and bovine serum albumin (BSA) using terbium-danofloxacin (Tb3+-Dano) as a fluorescent probe. These proteins remarkably enhance the fluorescence intensity of the Tb3+-Dano complex at 545 nm, and the enhanced fluorescence intensity of Tb3+-Dano is proportional to the concentration of proteins (HSA and BSA). Optimum conditions for the determination of HSA were investigated and found that the maximum response was observed at: pH = 7.8, [Tb3+] = 8.5 × 10−5 mol L−1, [Dano] = 1.5 × 10−4 mol L−1. The calibration graphs for standard solutions of BSA, HSA, and plasma samples of HSA were linear in the range of 0.2 × 10−6 − 1.3 × 10−6 mol L−1, 0.2 × 10−6 − 1.4 × 10−6 mol L−1, and 0.2 × 10−6 − 1 × 10−6 mol L−1, respectively. The detection limits (S/N = 3) for BSA, HSA, and plasma sample of HSA were 8.7 × 10−8 mol L−1, 6.2 × 10−8 mol L−1, and 8.1 × 10−8 mol L−1, respectively. The applicability of the method was checked using a number of real biological plasma samples and was compared with the UV spectrometric reference method. The results was showed that the method could be regarded as a simple, practical, and sensitive alternative method for determination of albumin in biological samples

A sensitive homogeneous enzyme assay for euchromatic histone-lysine-N-methyltransferase 2 (G9a) based on terbium-to-quantum dot time-resolved FRET

Introduction: Histone modifying enzymes include several classes of enzymes that are responsible for various post-translational modifications of histones such as methylation and acetylation. They are important epigenetic factors, which may involve several diseases and so their assay, as well as screening of their inhibitors, are of great importance. Herein, a bioassay based on terbium-to-quantum dot (Tb-to-QD) time-resolved Förster resonance energy transfer (TR-FRET) was developed for monitoring the activity of G9a, the euchromatic histone-lysine N-methyltransferase 2. Overexpression of G9a has been reported in some cancers such as ovarian carcinoma, lung cancer, multiple myeloma and brain cancer. Thus, inhibition of this enzyme is important for therapeutic purposes. Methods: In this assay, a biotinylated peptide was used as a G9a substrate in conjugation with streptavidin-coated ZnS/CdSe QD as FRET acceptor, and an anti-mark antibody labeled with Tb as a donor. Time-resolved fluorescence was used for measuring FRET ratios. Results: We examined three QDs, with emission wavelengths of 605, 655 and 705 nm, as FRET acceptors and investigated FRET efficiency between the Tb complex and each of them. Since the maximum FRET efficiency was obtained for Tb to QD705 (more than 50%), this pair was exploited for designing the enzyme assay. We showed that the method has excellent sensitivity and selectivity for the determination of G9a at concentrations as low as 20 pM. Furthermore, the designed assay was applied for screening of an enzyme inhibitor, S-(5’-Adenosyl)-L-homocysteine (SAH). Conclusion: It was shown that Tb-to-QD FRET is an outstanding platform for developing a homogenous assay for the G9a enzyme and its inhibitors. The obtained results confirmed that this assay was quite sensitive and could be used in the field of inhibitor screening

SPR signals enhancement by gold nanorods for cell surface marker detection

Introduction: The detection of micrometer-sized particles like cells is limited by surface plasmon resonance (SPR) biosensors because of having a depth of evanescent wave <500 nm. In this study, for the first time, we exhibited the use of streptavidin-functionalized gold nanorods (GNRs) as intensification labels for detection of cell surface markers in SPR-based biosensors. Methods: The GNRs (ʎ max: 735 nm) were modified with streptavidin using EDC/NHS coupling method and human umbilical vein endothelial cells (HUVECs) were selected as the cell model for detecting VE-cadherin on cell surface using real-time SPR device in the 785 nm wavelength of the laser source. Results: The investigations revealed that the plasmonic field extension produced from the gold layer and GNRs resulted in multiple enhancement of SPR signals when the wavelength of laser source in SPR instrument was matched with the wavelength of maximum absorbance in GNRs. Moreover, the results showed that the growth of ∆RU value in specific and non-specific bindings for various cell number injections were produced with increasing the cell number. Conclusion: The results displayed that cell detection can be performed in real- time form without any need to a time-consuming process used in conventional methods like immunocytochemistry, flow cytometry, and western blotting

The effect of Myo-inositol on sperm parameters and pregnancy rate in oligoasthenospermic men treated with IUI: A randomized clinical trial

Background: In about 40% of the couples, the cause of infertility problems is attributed to men because of low sperm production and disturbed motility of sperm. Pieces of evidence show that Myo-inositol has a potential role for the treatment of sperm morphology and male fertility. Objectives: This study aimed to determine the effect of Myo-inositol on the sperm parameters and fertility rate in patients with oligoasthenospermia treated by intrauterine insemination (IUI). Materials and Methods: This study was a randomized clinical trial conducted on 37 patients with oligoasthenospermia treated by IUI during 2016-2017. In this study, the patients were randomly divided into two groups of oligoasthenospermia treated with (Case group) and without Myo-inositol (Control group). The case group received 0.5 ml of Myo-inositol with a concentration of 2 mg/ml and incubated at 37°C incubator for 2 hr, but the control group had no interventions. Results: The results of this study showed that although there was no significant difference in sperm parameters including sperm motility and concentration before processing with Myo-inositol in the case group, but there was a significant increase in sperm motility during the treatment with Myo-inositol. The therapeutic effect of this method was confirmed on induction of pregnancy in 18% of the treated patients, in such a way that was about twice greater than those who did not receive the drug. Conclusion: According to the results of this study, the use of Myo-inositol is efficient enough to change sperm parameters to increase the chance of fertility. Key words: Myo-inositol, Pregnancy, Sperm, Motility, Oligoasthenospermic

Evaluation of Flavonoid Derivative and Doxorubicin Effects in Lung Cancer Cells (A549) Using Differential Pulse Voltammetry Method

Purpose: Electrochemical measurements have prompted the progress as a consequence of their affectability, cost-affectivity and comparatively short examination time. The aim of this study was the fast evaluation of the effect of chemotherapy compounds on the viability of lung cancer cells (A549) via electrochemical methods. Methods: Cyclic voltammetry (CV) was used as a primary method to distinguish between electrochemical behavior of normal and lung cancer cells. Differential pulse voltammetry (DPV) was employed as a complementary analyses method for the impact of doxorubicin (DOX) and Flavonoid modified drug (FMD) (US patent Application number: 62548886) on Lung cancer cells. Results: Only one oxidative peak, at approximately -0.15 V was detected through DPV method in cancer cell line. While a significant distinguish was not seen in CV. The current intensity (I) was decreased in cancer cells with increasing the DOX and FMD levels (t=99.027, α=0.05, P=0.0000), (t=135.513, α=0.05, P=0.0000), respectively. Conclusion: The movement of cancerous cells towards death through chemotherapy drugs such as DOX and FMD can make distinct and significant changes in the electrochemical behaviors of those cells

The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase 1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age  6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score  652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc = 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N = 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701

Electromagnetic Concepts to Enhance Communication in Harsh RF Environments

Given the limited spectrum resources, planning of the future wireless networks such as fifth generation and beyond to be deployed in very congested and complex electromagnetic environments requires techniques for efficient co-channel external and internal (self-) interference cancelation. Benefited from electromagnetic concepts, signal processing techniques, or combination of both, the first part of this research reports on workable solutions for 1) the mitigation of self-interference issue in wireless transceivers for enabling full-duplex communication and 2) the cancelation of external interference caused by the other users, multipath effects, or jammers. To develop the antenna system for enabling self-interference cancelation, in the first step, a compact, single-port slot antenna is designed which provides a minimum gain of 11 dB and an aperture efficiency of 65% over 40% fractional bandwidth. Next, the antenna is evolved to a common-aperture two-port antenna system with a very high level of isolation between channels over a wide bandwidth yet maintaining consistent radiation characteristics. A low-loss air-dielectric microstrip feed is designed which can be integrated with the other parts of the antenna and is amenable to 3D printing technology. The proposed decoupling method can potentially provide nearly 90 dB of channels isolation over 44% fractional bandwidth. For the fabricated antenna, a minimum isolation of 55 dB and a minimum gain of 10 dB is measured over the entire band. To manage external interference, novel array signal segregation algorithms have been developed to spatially retrieve the desired signals in the presence of strong interfering signals. Using a uniform circular array, the algorithms are formulated to account for mutual coupling among array elements. A frequency domain Array Signal Segregation using an Iterative Approach (ASSIA) is presented to estimate the directions of arrival, magnitudes and phases of the signals’ spectral components. A statistical analysis in a complex environment with Rayleigh fading characteristics shows that ASSIA radio with a 12-element circular array can improve the signal to jammer ratio from -20 dB to at least +2 dB in more than 70% of occasions. In conjunction with ASSIA, a super-resolution signal detection algorithm based on a novel Closely spaced Nulls Synthesis Method (CNSM) is then developed which, for the first time, demonstrates capability of an antenna array in resolving direction of arrival of closely spaced correlated signals in the absence of a priori knowledge of the number of the incident signals. It is demonstrated that the proposed ASSIA-CNSM is superior to the other super-resolution Directions of Arrivals (DoA) estimation techniques such as Maximum Likelihood method. To improve the performance of the proposed algorithms, an efficient feed-forward technique is presented to mitigate the mutual coupling effects in multiple antenna systems. Subsurface communication is another challenging task mainly due to the very lossy ground formations. In smart directional drilling, for instance, the existing telemetry methods do not meet the required data-rate for real time monitoring and controlling purposes. The second part of this work reports on a robust, cost-effective and high data-rate communication technique for enabling long-distance communication in drilling process. The concept of using the drilling tools as a Single Conductor Transmission Line (SCTL) is introduced and a very compact SCTL transducer that fits inside the borehole is designed at low HF band. The transducer provides 2% fractional bandwidth and can be used to enable data transmission at a data rate of 60 kbps.PHDElectrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/149873/1/smamjadi_1.pd