Core–Shell Nanoarchitectonics of CoFe2O4 Encapsulated La2Fe2O6 Nanoparticles for Their Use in Various Applications

It would be helpful to achieve appropriate synthetic routes to attain larger-scale production at industrial levels of nanocomposites at low costs. In the present work, diphasic composites with core–shell nanostructures formed by La₂Fe₂O₆/CoFe₂O₄ are investigated. The core–shell structure is fabricated via different preparation methods. The advantages and the demerits of the synthesis techniques are discussed. The presence of both the spinel CoFe₂O₄ nano ferrite and orthorhombic La₂Fe₂O₆ perovskite phases is revealed by X-ray diffraction. XPS spectroscopy is utilized to investigate the chemical composition of the prepared samples. The hysteresis loops of the prepared samples exhibit a smooth loop that is resulted from the existence of two homogeneous magnetic phases. For the first time, it has been found that the preparation conditions have the advantage of reducing the switching field distribution value for the core–shell nanoparticles. Exchange coupled core–shell nanoparticles present a high potential to regulate the magnetic properties for numerous applications such as heavy metal removal and/or data storage devices. The maximum adsorption capacity (qm) of Cr III on the core–shell (S3) is higher compared to other adsorbents previously testified in the literature. The cost-effective and eco-friendly prepared core–shell samples with good metal removal capacity have great potential for commercialization.

     

Morphological segmenting and neighborhood pixel-based locality preserving projection on brain fMRI dataset for semantic feature extraction: an affective computing study

Two specific chemical receptive fields of brain, namely the amygdala and the orbital-frontal cortex, are related to valence and arousal in medical experiments. Functional magnetic resonance imaging (fMRI), which is a noninvasive, repeatable, and atomical tool for medical imaging in clinic system, was widely used in affective computing; however, it faces its dataset processing difficulty for dimensional reduction as well as for decreasing the computational complexity. In addition, features extraction from those de-dimensionality datasets is a challenging issue. The current work solved the de-dimensionality issue by using some preprocessing algorithms including clustering, morphological segmenting, and locality preserving projection. In order to keep useful information in fMRI dataset for reduction process, improved neighborhood pixel-based locality preserving projection (NP-LPP) algorithm was addressed and continuously for feature extraction operating using Otsu weighted sum of histogram. Furthermore, a modified covariance power spectral density (MC-PSD) separately in an fMRI Valence–Arousal experiments was measured. The results were analyzed and compared with affective norms English words system. The experiments established that the proposed methods of NP-LPP effectively simplified high complexity of fMRI, and Otsu weighted sum of histogram exhibited superior performance for features extraction compared to the MC-PSD through the calculation root mean standard error. The current proposed method provided a potential application and promising research direction on human semantic retrieval through medical imaging dataset.

     

The tale of proteolysis targeting chimeras (PROTACs) for Leucine-Rich Repeat Kinase 2 (LRRK2)

Here we present the rational design and synthetic methodologies towards proteolysis-targeting chimeras (PROTACs) for the recently-emerged target leucine-rich repeat kinase 2 (LRRK2). Two highly potent, selective, brain-penetrating kinase inhibitors were selected, and their structure was appropriately modified to assemble a cereblon-targeting PROTAC. Biological data show strong kinase inhibition and the ability of the synthesized compounds to enter the cells. However, data regarding the degradation of the target protein are inconclusive. The reasons for the inefficient degradation of the target are further discussed.     

In-vitro evaluation of wollastonite nanopowder produced by a facile process using cheap precursors for biomedical applications

Wollastonite nanopowder (β-CaSiO₃) is the most nanoceramic powder that is most frequently applied in biomedical applications due to its good bioactivity and biocompatibility. Although the preparation of wollastonite in a solid-state is distinguished as a simple and cheap method with large-scale production, it requires high temperatures (=1400 °C) and consumes quite a long time. The wet methods are considered the best when it comes to preparing the wollastonite nanopowders. However, it has some drawbacks such as its extravagant raw materials and its shorting in preparation which inhibits successful coverage for large-scale production. Herein facile, one-pot modified co-precipitation approach with an easy procedure, shorter reaction time, and in-expensive precursor sodium meta-silicate-pentahydrate and CaCO₃ has been utilized for large-scale production of wollastonite nano-powders (76–150 nm). The precipitated product was calcined at different temperatures (800, 900, 1000, and 1100 °C). The phase composition and microstructure of the calcined powders were investigated. They were analyzed by XRD, FTIR, FESEM, and HRTEM. The in-vitro bioactivities of the calcined powders at 1000 &1100 °C were investigated by analyzing their abilities to form apatite on their surface after 21 days in SBF. The apatite mineralization of the powder surfaces was examined through FESEM, EDX, and Raman spectra. The results show that a single-phase wollastonite got formed at all calcined temperatures with a unique silkworm texture. SBF in-vitro test states the formation of HA on the powder surface. Therefore, these powders are expected to be valuable and promising for biomedical applications such as coating and bio cement.     

Texture anisotropy technique in brain degenerative diseases

Structural alterations anisotropy-based measured for different areas for the most common types of dementia diseases could be a biomarker of brain impairment. The current work aims to assess whether texture anisotropy can discriminate both healthy versus Alzheimer’s and Pick’s patients based on regional evaluation while maintaining high predictive power. The investigated area is reduced from the whole-brain surface to three major lobes (i.e., frontal, temporal and parietal). A predictive model was proposed to associate a disease with a specific area in the brain based on the anisotropy values. Simultaneous analysis of 1680 measurements from 105 brain magnetic resonance images acquired as T2w and PD sequences was performed to establish the significance of the model. The cerebral calcinosis disease has been used as artificial ground truth. The association based on textural anisotropy between targeted diseases and control patients was performed by using Pearson’s correlation coefficients. A new proposed consistency index investigated the texture anisotropy relevance for all image’s types and all analyzed classes and regions. The validation study is based on area under the receiver-operating characteristic curve that depicted the overall diagnostic performance of the texture anisotropy in each region. The proposed model demonstrated that texture anisotropy is accurate solution in diagnosis of Alzheimer’s and Pick’s diseases when the investigated area is reduced to major lobes, with sensitivity >90% and specificity >80%.

     

On the Effect of Carbon Nano-Tubes Addition on Structure and Superconducting Properties of Bi(Pb)-2223 Phase

In this work, a series of ceramic samples of Bi_1.6Pb_0.4Sr₂Ca₂Cu₃O _y (Bi(Pb)-2223) added with different amounts (0, 0.2 and 0.4 wt%) of carbon nano-tubes (CNT) are prepared from commercial powders and characterized. The study shows that the volume fraction of the Bi(Pb)-2223 phase decreases with CNT content while the grain size of the samples increases. The obtained cell parameters as well as the onset critical transition temperature are independent of this kind of addition. Also, it has been concluded that CNT addition makes the grains of the samples more connected. The measured magnetization in FC and ZFC modes indicates that CNT addition makes the grains of the samples more connected even if the irreversibility line is decreased. The variation of the residual resistivity and metalicity with CNT content suggests that the addition introduces disorder and defects into the samples. Also, the added samples present broad transitions to the superconducting state when compared to the pure one; this result may be associated to the increase of the volume fraction of the secondary phases. The activation energies, upper critical fields H _c2(0) and coherence lengths ξ(0) are extracted from the magneto-resistivity curves and their evolutions with CNT content are discussed.     

利用帧头消除测距时标整周期滑动的方法

在弹载扩频脉冲应答式测距系统中,应答机直接利用捕获脉冲作为时标信号进行测距。此法在高信噪比时测距精度较高,但在低信噪比时,伪码同步脉冲的抖动较大,同时捕获脉冲会产生整数个伪码周期地滑动,导致测距误差较大。为了提高测距精度,提出了一种利用帧头消除脉冲应答式测距时标整周期滑动并降低时钟抖动的方法。在获得伪码捕获脉冲并检测到帧头后,应答机才启动应答信号,可有效降低低信噪比时的测距误差。