Structural, Magnetic and Microwave Properties of Eu-doped Barium Hexaferrite Powders

Eu-doped M-type barium ferrite powders (Ba_1−x Eu _x Fe₁₂O₁₉) with x=0.0, 0.1, 0.2 and 0.25 were prepared by sol-gel method. The synthesized samples are characterized by thermo gravimetric analysis (TG-DTA), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and vector network analyzer. All the synthesized samples have the nearly single-magnetoplumbite phase. The results show that the crystallite size of doped samples is smaller than pure one. The saturation magnetization of doped ferrites decreases by the increase in Eu doping, while the coercivity increases. Maximum coercivity achieved in this study is 6.12 KOe for x=0.25 sample. The enhancement of coercivity by Eu doping is mainly due to the higher magnetocrystalline anisotropy, which is attributed to the partial change of Fe⁺³ ion to Fe⁺² ion. The maximum reflection loss (RL) of −43 dB at frequency range of 12–18 GHz for the x=0.1 sample was obtained. The increase in reflection loss at higher frequency suggests that the Eu-doped sample can be used for the application in microwave devices.     

Polyhydroxybutyrate/chitosan/bioglass nanocomposite as a novel electrospun scaffold: fabrication and characterization

Scaffolds and their features play a central role in tissue engineering; so this study is based on the production of a series of electrospun PHB/Chitosan/nBG nanocomposite scaffolds with 9 wt% polyhydroxybutyrate, 10, 15 and 20 wt% chitosan and 7.5, 10 and 15 wt% nanobioglass (nBG). Electrospinning process was performed with optimal conditions of spinning machine including voltage of 16 kV, syringe-collector spacing of 16 cm, and output rate of 1 µl per hour. The developed phases and the formation of chemical bonds between ceramic and polymer bands were studied through XRD and FTIR analyses. The FE-SEM and TEM analyses showed uniform morphology of nanofibers and dispersion of bioglass nanoparticles in the fiber structure. The presence of 10 wt% bioglass nanoparticles and 15 wt% chitosan increased the tensile strength of fibers to 3.42 MPa, which was about four times greater than strength of control sample (pure PHB). The developed fibers were kept 28 days in SBF solution and 60 days in PBS solution to assess their bioactivity and biodegradability. The results showed that the presence of bioglass nanoparticles leads to a dramatic increase in absorption of calcium and phosphorus ions and weight loss of scaffold. The developed scaffold can be used for bone and teeth tissue engineering applications.     

Effects of Recycling on the Mechanical Behavior of Polypropylene at Room Temperature Through Statistical Analysis Method

This article reports the effects of recycled material percentage, annealing conditions, and glass fiber percentage on the mechanical behavior of injection molded polypropylene samples. Specimens were prepared with different percentages of recycled material ranging from 0 to 100%. Two groups of samples, i.e., non‐annealed and annealed at 150°C, were tested to investigate annealing effects. The effects of adding fiber (0–7.5%) to specimens was also investigated. It was found that increasing the amount of recycled material improves the material properties in a non‐linear trend. Annealing had a significant positive effect on both non‐fiber‐added and fiber‐added samples: it improved the yield stress of non‐reinforced polypropylene samples by more than 10% and their Young's modulus by about 50%. Fiber‐added materials showed more variability, and adding fiber also improved the Young's modulus and the yield stress of the samples by about 50%. The results indicate that the three factors investigated improved toughness of the injected polypropylene samples; however the effects are not significant. The study findings reveal that using recycled polypropylene has no significant effect on the material properties of polypropylene. POLYM. ENG. SCI., 56:1283–1290, 2016 © 2016 Society of Plastics Engineers     

Photobiomodulation Therapy and the Glymphatic System: Promising Applications for Augmenting the Brain Lymphatic Drainage System

The glymphatic system is a glial-dependent waste clearance pathway in the central nervous system, devoted to drain away waste metabolic products and soluble proteins such as amyloid-beta. An impaired brain glymphatic system can increase the incidence of neurovascular, neuroinflammatory, and neurodegenerative diseases. Photobiomodulation (PBM) therapy can serve as a non-invasive neuroprotective strategy for maintaining and optimizing effective brain waste clearance. In this review, we discuss the crucial role of the glymphatic drainage system in removing toxins and waste metabolites from the brain. We review recent animal research on the neurotherapeutic benefits of PBM therapy on glymphatic drainage and clearance. We also highlight cellular mechanisms of PBM on the cerebral glymphatic system. Animal research has shed light on the beneficial effects of PBM on the cerebral drainage system through the clearance of amyloid-beta via meningeal lymphatic vessels. Finally, PBM-mediated increase in the blood–brain barrier permeability with a subsequent rise in Aβ clearance from PBM-induced relaxation of lymphatic vessels via a vasodilation process will be discussed. We conclude that PBM promotion of cranial and extracranial lymphatic system function might be a promising strategy for the treatment of brain diseases associated with cerebrospinal fluid outflow abnormality.     

Correlation analysis techniques for uncertain time series

Many applications such as location-based services and wireless sensor networks generate and deal with uncertain time series (UTS), where the “exact” value at each timestamp is unknown. Traditional correlation analysis and search techniques developed for standard time series are inadequate for UTS data analysis required in such applications. Motivated by this need, we propose suitable concepts and techniques for UTS correlation analysis. We formalize the notion of normalization and correlation for UTS in two general settings based on the available information at each timestamp: (1) PDF-based UTS (having probability density function) and (2) multiset-based UTS (having multiset of observed values). For each case, we formulate correlation as a random variable and develop techniques to determine the underlying probability density function. For setup (2), we also present probabilistic pruning and sampling techniques to speed up the search process. We conducted numerous experiments to evaluate the performance of the proposed techniques under different configurations using the UCR benchmark datasets. Our results indicate effectiveness of the proposed techniques. For setup (2), in particular, our results show significant improvement in space utilization and computation time. We believe the proposed ideas and solutions lend themselves to powerful tools for UTS analysis and search tasks.     

Survey of Irrigation Methods in California in 2001

Reliable information on irrigation methods is important for determining agricultural water demand trends. Therefore, a study was conducted during 2002 to collect information on irrigation methods that were used by growers to irrigate their crops in 2001. The results were compared to earlier surveys to assess trends in cropping and irrigation methods. A one-page questionnaire was developed to collect information on irrigated land by crop and irrigation methods. The questionnaire was mailed to 10,000 growers in California that were randomly selected from a list of 58,000 growers by the California Department of Food and Agriculture, excluding rice, dry-land, and livestock producers. From 1972 to 2002, the area planted has increased from 15 to 31% for orchards and from 6 to 16% for vineyards. The area planted to vegetables has remained relatively static, while that planted to field crops has declined from 67 to 42% of the irrigated area. The land irrigated by low-volume (drip and microsprinkler) irrigation has increased by about 33%, while the amount of land irrigated by surface methods has decreased by about 31%. Sprinkler usage has decreased in orchards and vineyards, but it has increased in vegetable crops.     

Emerging Functions for snoRNAs and snoRNA-Derived Fragments

The widespread implementation of mass sequencing has revealed a diverse landscape of small RNAs derived from larger precursors. Whilst many of these are likely to be byproducts of degradation, there are nevertheless metabolically stable fragments derived from tRNAs, rRNAs, snoRNAs, and other non-coding RNA, with a number of examples of the production of such fragments being conserved across species. Coupled with specific interactions to RNA-binding proteins and a growing number of experimentally reported examples suggesting function, a case is emerging whereby the biological significance of small non-coding RNAs extends far beyond miRNAs and piRNAs. Related to this, a similarly complex picture is emerging of non-canonical roles for the non-coding precursors, such as for snoRNAs that are also implicated in such areas as the silencing of gene expression and the regulation of alternative splicing. This is in addition to a body of literature describing snoRNAs as an additional source of miRNA-like regulators. This review seeks to highlight emerging roles for such non-coding RNA, focusing specifically on “new” roles for snoRNAs and the small fragments derived from them.     

Observation of targeted gold nanoparticles in nasopharyngeal tumour nude mice model through dual‐energy computed tomography

This study was performed to specify the efficiency of imaging nanoparticle concentration as contrast media in dual‐energy computed tomography (DECT). Gold nanoparticles (AuNPs) and gold nanoparticles‐conjugated folic acid through cysteamine (FA‐Cya‐AuNPs) were both considered as contrast agents. Characterization of NPs was performed using Dynamic Light Scattering (DLS) and zeta potential. The hemocompatibility of NPs was confirmed by different blood parameters such as white blood cell, red cell distribution width, hemoglobin, lymphocytes counts and haemolysis assay. DECT algorithm was confirmed using calibration phantom at different concentrations of NPs and tube potentials (80 and 140 kVp). Then, DECT was used to quantify the concentration of both AuNPs and FA‐Cys‐AuNPs in human nasopharyngeal cancer cells. Mice were injected with non‐targeted AuNPs and targeted AuNps at a concentration of 3 × 10³ μg/ml. Then, they were scanned with different tube potentials. The concentration of nanoparticles in the various organs of nude mice was measured through DECT imaging and inductively coupled plasma mass spectrometry (ICP‐MS) analysis. The results of DECT images were compared with ICP‐MS analysis and indicated that they were approximately similar. In sum, FA‐Cys‐AuNPs can be a proper candidate for targeted contrast media in DECT molecular scanning of human nasopharyngeal tumours.     

Abnormal Deformation Behavior of Oxygen-Modified <Emphasis Type="Italic">β</Emphasis>-Type Ti-29Nb-13Ta-4.6Zr Alloys for Biomedical Applications

Oxygen was added to the biomedical β-type Ti-29Nb-13Ta-4.6Zr alloy (TNTZ, mass pct) in order to improve its strength, while keeping its Young’s modulus low. Conventionally, with an increase in the oxygen content, an alloy’s tensile strength increases, while its tensile elongation-to-failure decreases. However, an abnormal deformation behavior has been reported in the case of oxygen-modified TNTZ alloys in that their strength increases monotonically while their elongation-to-failure initially decreases and then increases with the increase in the oxygen content. In this study, this abnormal tensile deformation behavior of oxygen-modified TNTZ alloys was investigated systematically. A series of TNTZ-(0.1, 0.3, and 0.7 mass pct)O alloy samples was prepared, treated thermomechanically, and finally solution treated; these samples are denoted as 0.1ST, 0.3ST, and 0.7ST, respectively. The main tensile deformation mechanisms in 0.1ST are a deformation-induced α″-martensitic transformation and {332}〈113〉 mechanical twinning. The large elongation-to-failure of 0.1ST is attributable to multiple deformation mechanisms, including the deformation-induced martensitic transformation and mechanical twinning as well as dislocation glide. In both 0.3ST and 0.7ST, dislocation glide is the predominant deformation mode. 0.7ST shows more homogeneous and extensive dislocation glide along with multiple slip systems and a higher frequency of cross slip. As a result, it exhibits a higher work-hardening rate and greater resistance to local stress concentration, both of which contribute to its elongation-to-failure being greater than that of 0.3ST.