Vibration‐Induced Deagglomeration and Shear‐Induced Alignment of Carbon Nanotubes in Air

Carbon nanotubes (CNTs) are widely known to agglomerate into difficult to separate, 10–100 μm bundles, even after suspension in solution. Here, a dry and rapid (≈10 s) method to deagglomerate bulk, unbound multi‐walled CNT bundles due to surface acoustic waves (SAW) in a piezoelectric substrate is reported for the first time. The process first forms 1‐μm CNT bundles from extremely large (≈10 Mm/s²) mechanical accelerations due to the SAW; these bundles are consequently susceptible to SAW‐induced evanescent, quasistatic electric fields that couple into the bundles and form a mat of long (1–10 μm) individual CNTs on the substrate surface. These CNTs may then be aligned along the direction of shear provided by sliding a glass cover slip 10 mm across the CNT mat. This alignment is notably independent of the SAW propagation direction. Further, the intrinsic structure of the nanotubes is unaffected as verified using Raman spectroscopy. Uniquely simple, the approach avoids the many shortcomings of other CNT deagglomeration techniques—particularly surface modification and suspension in solution—to rapidly separate and align large numbers of CNTs, thereby overcoming a key limitation in their use for a diverse range of applications.     

Energy-Efficient Routing Using Novel Optimization with Tabu Techniques for Wireless Sensor Network

Wireless Sensor Network (WSN) consists of a group of limited energy source sensors that are installed in a particular region to collect data from the environment. Designing the energy-efficient data collection methods in large-scale wireless sensor networks is considered to be a difficult area in the research. Sensor node clustering is a popular approach for WSN. Moreover, the sensor nodes are grouped to form clusters in a cluster-based WSN environment. The battery performance of the sensor nodes is likewise constrained. As a result, the energy efficiency of WSNs is critical. In specific, the energy usage is influenced by the loads on the sensor node as well as it ranges from the Base Station (BS). Therefore, energy efficiency and load balancing are very essential in WSN. In the proposed method, a novel Grey Wolf Improved Particle Swarm Optimization with Tabu Search Techniques (GW-IPSO-TS) was used. The selection of Cluster Heads (CHs) and routing path of every CH from the base station is enhanced by the proposed method. It provides the best routing path and increases the lifetime and energy efficiency of the network. End-to-end delay and packet loss rate have also been improved. The proposed GW-IPSO-TS method enhances the evaluation of alive nodes, dead nodes, network survival index, convergence rate, and standard deviation of sensor nodes. Compared to the existing algorithms, the proposed method outperforms better and improves the lifetime of the network.     

Racial microaggressions in the life experience of Black Americans.

Racial microaggressions cause considerable psychological distress among Black Americans and are manifested in nearly all interracial encounters. They set in motion energy-depleting attempts to determine whether incidents were racially motivated. Reactions can be classified into 4 major themes: healthy paranoia, sanity check, empowering and validating self, and rescuing offenders. Microaggressions result in high degrees of stress for Blacks because of denigrating messages: "You do not belong," "You are abnormal," "You are intellectually inferior," "You cannot be trusted," and "You are all the same." Feelings of powerlessness, invisibility, forced compliance and loss of integrity, and pressure to represent one's group are some of the consequences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Racial microaggressions in everyday life: Implications for clinical practice.

Racial microaggressions are brief and commonplace daily verbal, behavioral, or environmental indignities, whether intentional or unintentional, that communicate hostile, derogatory, or negative racial slights and insults toward people of color. Perpetrators of microaggressions are often unaware that they engage in such communications when they interact with racial/ethnic minorities. A taxonomy of racial microaggressions in everyday life was created through a review of the social psychological literature on aversive racism, from formulations regarding the manifestation and impact of everyday racism, and from reading numerous personal narratives of counselors (both White and those of color) on their racial/cultural awakening. Microaggressions seem to appear in three forms: microassault, microinsult, and microinvalidation. Almost all interracial encounters are prone to microaggressions; this article uses the White counselor-client of color counseling dyad to illustrate how they impair the development of a therapeutic alliance. Suggestions regarding education and training and research in the helping professions are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of tigernut (Cyperus esculentus) flour addition on the quality of wheat‐based cake

The effect of substituting tigernut flour for wheat flour on the proximate, mineral and pasting properties of the resultant blends and cake quality were studied. The proximate composition of flour blends increased with increasing level of tigernut. Protein increased from 22.30 to 26.93% and fat from 4.17 to 7.21% resulting in an increase in energy value from 342.09 to 390.93 kcal. The pasting properties of the flour blends were affected significantly (P ≤ 0.05) by tigernut substitution. Pasting peak time and temperature decreased with increasing level of tigernut. Mineral elements such as iron and calcium increased from 3.13 to 4.19 and 54.01 to 56.41 (mg 100 g^?1) respectively, with tigernut substitution. The weight and volume of cakes increased with tigernut level while batter density and volume index decreased. Acceptable cakes can be made with up to 30% tigernut flour substitution. Such composite cakes may help in reducing protein energy and micronutrient deficiencies.     

Leptin Protein Expression and Promoter Methylation in Ovarian Cancer: A Strong Prognostic Value with Theranostic Promises

Ovarian cancer (OC) is the deadliest among all gynecological cancers. Epidemiological studies showed that obesity might influence many cancers including OC. One of the key factors that may link obesity and OC is leptin (LEP), known as an adipokine with pleiotropic effects on body homeostasis. This study aims to investigate the expression pattern of LEP, assess the methylation profiles of LEP and their associations with clinicopathological features including survival outcomes of OC patients. The protein expression of LEP was evaluated in 208 samples using both tissue microarray and immunohistochemistry techniques. The methylation profiles of LEP were measured in 63 formalin-fixed, paraffin-embedded tumor tissues by quantitative polymerase chain reaction using a MethyLight assay. Our results showed a significant association of LEP protein overexpression with several clinicopathological variables, mainly tumor subtype, LVI, age of menarche, tumor size and stage (p < 0.04). Kaplan–Meier analysis (using low expression versus high expression as a discriminator) indicated that LEP protein overexpression is a powerful positive prognosticator of both OC recurrence (DFS) and disease-specific survival (DSS) in our OC cohort (log-rank p = 0.01 and p = 0.002, respectively). This implies that patients with high LEP expression profiles live longer with less recurrence rates. Methylation analysis results demonstrated a clear association between no/low LEP protein expression pattern (38%) and LEP promoter CpG island hypermethylation (43%). Results of this study suggest that LEP is a powerful prognosticator of OC recurrence and DSS. LEP expression in OC seems to be regulated by its promoter hypermethylation through gene partial/total silencing. Further multi-institutional studies using larger cohorts are required to demystify the intricate molecular functions of this leptin-driven effects in OC pathophysiology and to accurately assess its theranostic potential and validate its prognostic/predictive power in OC onset, progression towards more effective and personalized management of OC patients.     

Effect of glucose on the stability of fresh mutton during storage at ambient temperature (25 ± 2 °C)

The feasibility of using d-glucose to extend the shelf life of fresh mutton at 25 ± 2 °C was investigated. Aqueous solutions of 5% d-glucose (w/v) containing 1000 ppm potassium sorbate, when applied on acidulant-treated mutton, are able to inhibit spoilage by delaying proteolytic activity, as seen by significantly lower (P < 0.01) levels of biogenic amines until 4 days of storage. Though there was no significant change in standard plate count during storage, as compared with a 1 day control, Enterobacteria were significantly (P < 0.01) inhibited. Cadaverine, the marker for threshold level of spoilage, was absent up to 4 days. Measurement of glucose retention revealed that 0.25% (0.25 g/100 g mutton) was still available at the end of 4 days, when no spoilage had set in, though there was a slight fermented odour. Thus, the investigation shows that, surface treatment with glucose helps to extend the shelf life of fresh mutton up to 3 days at 25 ± 2 °C.     

Infrared study of the thermal behavior of γ-irradiated poly-(vinyl alcohol)

Infrared spectroscopy was applied for the investigation of the combined effects of γ-irradiation and heat on polyvinyl alcohol (PVA). The samples were exposed in an atmosphere of air at room temperature to doses ranging form 0.5 to 15 M rads. The obtained results revealed that exposure to γ-irradiation produces no considerable changes in the IR spectra of PVA apart from very slight changes in the intensities of the absorption bands. The crystallinity of the irradiated samples was determined by following the induced changes in the absorbances of the crystalline bands. The IR spectra of PVA samples heated at 180°C exhibited two absorption bands at 1580 and 1710 cm^?1 due to carbonyl groups. Alken double bonds and possibly also carboxyl groups. IR spectroscopy was also used for the examination of the effect of time of heating in air or in vacuum and also the effect of quenching of the degree of crystallinity of γ-irradiated PVA. Careful examination of the IR spectra led to the conclusion that the temperature induced changes depend on time of heating, rate of cooling and γ-dosage used. The highest crystallinity was obtained by heating in vacuum at 140°C and quenching at ?40°C.     

Novel Algorithm for Mobile Robot Path Planning in Constrained Environment

This paper presents a development of a novel path planning algorithm, called Generalized Laser simulator (GLS), for solving the mobile robot path planning problem in a two-dimensional map with the presence of constraints. This approach gives the possibility to find the path for a wheel mobile robot considering some constraints during the robot movement in both known and unknown environments. The feasible path is determined between the start and goal positions by generating wave of points in all direction towards the goal point with adhering to constraints. In simulation, the proposed method has been tested in several working environments with different degrees of complexity. The results demonstrated that the proposed method is able to generate efficiently an optimal collision-free path. Moreover, the performance of the proposed method was compared with the A-star and laser simulator (LS) algorithms in terms of path length, computational time and path smoothness. The results revealed that the proposed method has shortest path length, less computational time and the best smooth path. As an average, GLS is faster than A* and LS by 7.8 and 5.5 times, respectively and presents a path shorter than A* and LS by 1.2 and 1.5 times. In order to verify the performance of the developed method in dealing with constraints, an experimental study was carried out using a Wheeled Mobile Robot (WMR) platform in labs and roads. The experimental work investigates a complete autonomous WMR path planning in the lab and road environments using a live video streaming. Local maps were built using data from a live video streaming with real-time image processing to detect segments of the analogous-road in lab or real-road environments. The study shows that the proposed method is able to generate shortest path and best smooth trajectory from start to goal points in comparison with laser simulator.     

Polymer-coated CoFe<Subscript>2</Subscript>O<Subscript>4</Subscript> nanoassemblies as biocompatible magnetic nanocarriers for anticancer drug delivery

In this work, we report the preparation of cobalt ferrite nanoparticles (CFNPs) coated with hydrophilic polymers guar gum, gum arabic and poly (methacrylic acid) as magnetic nanocarriers and study their conjugation with doxorubicin for the drug release under applied magnetic field. The effect of polymer coating on structural properties is studied using Fourier transform infrared spectroscopy and powder X-ray diffractometry (XRD). The XRD analysis revealed that the polymer coating on the as-synthesized CFNPs has no influence on their crystallite size and it remains between 18 nm and 19 nm. The characteristic morphology, topography and the evidences of polymer coating over the CFNPs are investigated using scanning electron microscopy, atomic force microscopy and thermogravimetric analysis, respectively. Vibrating sample magnetometry revealed the ferromagnetic nature of uncoated CFNPs with a significant saturation magnetization ～77.2 emu g^?1. The dynamic light scattering measurements are also performed to determine the size of uncoated and coated CFNPs. UV–Visible spectroscopy demonstrated a profound loading (70–75%) of doxorubicin onto the magnetic nanocarriers and the efficient release of drug in the presence of external applied magnetic field. In vitro cytotoxic studies confirmed the cytocompatibility mode of coated CFNPs against Chinese Hamster Ovary and Huh-7 cell line, while 0.2 mg mL^?1 dose of drug-loaded magnetic nanocarriers inhibited the cell viability of Huh-7 up to 60%. These results strongly encourage the utilization of biocompatible magnetic nanocarriers in targeted drug delivery territory.