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This paper describes a multiple-input multiple-output (MIMO) antenna for low millimeter (mm)-wave applications based on dielectric resonators. This is the first time that a filtering response is used in conjunction with an MIMO antenna operating at a low mm-wave frequency. The antenna is simulated using an asymmetrical U-shaped aperture and a microstrip line feed. The suggested filtenna has two distinguishing characteristics: (i) the diversity parameters of the proposed MIMO are increased by including pattern and spatial diversity, and (ii) the proposed feed mechanism of a dielectric resonator provides the filtering response. Between the two ports, a metallic plate tilts the radiation pattern by 45°. The anti-parallel locations of the ports increase the isolation value by >30 dB. To validate the performance of the suggested antenna, the proposed filtenna was built and confirmed. The proposed antenna operates between the frequencies 27.9 and 28.5 GHz. Within the operating frequency range, the observed gain is ~4.5 dBi. On the contrary, the gain suppression level beyond the operational frequency range is ~15 dB. The stable radiation properties and high diversity parameter values of the suggested filtenna make it an effective solution for 5G Internet of Things sensing applications.
To investigate the relative contributions of cerebral cortex and basal ganglia to movement stopping, we tested the optimum combination Stop Signal Reaction Time (ocSSRT) and median visual reaction time (RT) in patients with Alzheimer’s disease (AD) and Parkinson’s disease (PD) and compared values with data from healthy controls.
Thirty-five PD patients, 22 AD patients, and 29 healthy controls were recruited to this study. RT and ocSSRT were measured using a hand-held battery-operated electronic box through a stop signal paradigm.
The mean ocSSRT was found to be 309 ms, 368 ms, and 265 ms in AD, PD, and healthy controls, respectively, and significantly prolonged in PD compared to healthy controls (p = 0.001). The ocSSRT but not RT could separate AD from PD patients (p = 0.022).
Our data suggest that subcortical networks encompassing dopaminergic pathways in the basal ganglia play a more important role than cortical networks in movement-stopping. Combining ocSSRT with other putative indices or biomarkers of AD (and other dementias) could increase the accuracy of early diagnosis.
Aortopulmonary window is a rare congenital heart defect. Left main coronary artery extrinsic compression by an enlarged pulmonary artery is a rare complication and a potential cause for chest pain and sudden cardiac death in patients with pulmonary hypertension. Here, we present the case of a 14-year-old boy with a large aortopulmonary window who was planned for a device closure, but during the procedure, he developed ST-T segment changes while the device was being deployed, and hence the procedure was abandoned. The boy subsequently underwent a successful surgical closure thereafter.
In this study, nano-hydroxyapatite (n-HAp) of average crystallite size ∼8.15 ± 4 nm of hexagonal geometry with size ranging between 14 and 50 nm was synthesized in laboratory at room temperature by using suitable sources of calcium and phosphate ions and using triethanolamine. Mesoporous bioactive glass (MBG) was synthesized by using cationic surfactant cetyl trimethyl ammonium bromide of the SiO2–CaO–P2O5 glass system. After calcination at 650 °C, MBG powders were having a zeta potential of −16.5 mV (pH ∼9.1), median particle size ∼75 nm, and specific surface area 473.2 m2/g. An aqueous suspension of DNA was used to disperse both n-HAp and MBG and further subjected for analysis including absorbance, circular dichroism spectroscopy, UV-melting, and isothermal titration calorimetry. Absorbance spectroscopy indicated that an equilibrium binding was obtained between both materials and DNA in solution phase. Due to the addition of the nanomaterial, molar ellipticity of DNA was changed revealing that the materials were interacted with DNA. From UV melting characterization, there is a shifting of the melting temperature of DNA in the presence of MBG and n-HAp, respectively, suggesting that the nanoparticles stabilized DNA helix to a considerable extent.
This work focuses on the syntheses of Zn-enriched PtZn nanoparticle electrocatalysts by solution combustion for ethanol oxidation reaction (EOR). Analytical techniques of x-ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy, TEM/scanning TEM-energy dispersive x-ray spectroscopy, and x-ray photoelectron spectroscopy are used for the characterization of electrocatalysts. Cyclic voltammetry and chronoamperometry are applied for the electrocatalysis of C2H5OH and stability test in an alkaline medium, respectively. Electrochemical data show that PtZn/C has improved electrocatalytic activity by ~2.3 times compared with commercial Pt/C, in addition to having earlier onset potential and better stability for EOR. The variation of fuel amount in the synthesis has affected crystallite sizes, electronic, and electrochemical properties in electrocatalysts.
This paper reports the effect of Ar molar flow-rate on thermodynamic efficiency analysis of zinc oxide-zinc sulfate (ZnS-ZnO) water splitting cycle useful for solar H2 production. The thermodynamic efficiency analysis is conducted using the HSC Chemistry 7.1 software and its thermodynamic database. Influence of Ar molar flow-rate on total solar energy input essential for the continuous operation of the cycle is explored. Furthermore, the solar-to-fuel energy conversion efficiency for the ZnS-ZnO water splitting cycle is determined.
Chronic osteomyelitis, a bone infection caused by bacteria, requires extensive parenteral treatments. With an aim to develop bioactive glass with antibacterial properties to resist such infections, bioactive glasses with bismuth oxide as the dopant in various amounts up to 8 wt% were prepared. X-ray diffraction patterns and Fourier-transform infrared spectra of glass samples after immersion in simulated body fluid showed the presence of hydroxyapatite (HAp) and hydroxyl carbonate apatite for all samples except with the one having Bi2O3 substitution of 8 wt%. In vitro cell proliferation by MTT assay studies using a mouse fibroblast cell line (NIH3T3) have also been carried out. Primary antimicrobial activity of the glass particles was analyzed against Escherichia coli (E. coli) using broth microdilution method which exhibited bacteriostatic effects and bactericidal properties in selected samples. The combination of bioactivity, cell proliferation, and antibacterial properties of selected Bismuth-containing bioactive glasses could be exploited in treating bone-related infections.
In this study, Ni based ferrite nanomaterials were synthesized using sol-gel method for solar thermochemical splitting of CO2 using a thermogravimetric analyzer. To synthesize the ferrite materials, the corresponding metal precursors were dissolved in ethanol (with required molar ratios). After achieving the dissolution, propylene oxide (PO) was added to achieve the gel formation. Freshly synthesized gels were aged, dried, and calcined by heating up to 600°C in air. Powder x-ray diffractometer (XRD), BET surface area, as well as scanning (SEM) and transmission (TEM) electron microscopy characterized the calcined powders. The sol-gel derived ferrites were further tested towards their thermal reduction and CO2 splitting ability using a high temperature thermogravimetric analyzer (TGA).
This contribution reports the synthesis and characterization of La-based perovskites which can be used for the production of syngas via solar thermochemical splitting of H2O/CO2. The La-based perovskites were synthesized using a solution combustion synthesis approach. The derived perovskites were analyzed using powder X-ray diffractometer (PXRD), BET surface area analyzer (BET), and scanning/transmission electron microscope (SEM/TEM). The results associated with the synthesis and characterization of La-based perovskites is reported in detail.
The present work discusses about the mechanical and metallurgical properties of Incoloy 800 H friction welded joints. The process parameters namely friction pressure, friction time, upsetting pressure, upset time, and rotational speeds were varied from low level to high level to study their effects on the properties of the weldments. The tensile tests were carried out at four different temperatures namely at room temperature, 550, 650, and 750 °C. From the results, it is observed that as the testing temperature increased, there was a reduction in tensile strength of welds. The friction welds had higher hardness than the base metals. This was due to the formation of secondary phases (γ′ and M23C6) in friction welds. The tensile and impact fracture surfaces were further analyzed through SEM and finally the individual effects of the parameters with respect to the microstructures variation in the welds were studied.
Specific antibody responses were assessed in pigs immunized with the Taenia solium vaccine TSOL18. Anti-TSOL18 responses were compared 2 weeks after secondary immunization, where the interval between primary and secondary immunization was 4, 8, 12, 16 or 20 weeks. All animals responded to the vaccine and there was no diminution in antibody responses in animals receiving their second injection after an interval up to 20 weeks. Pigs receiving vaccinations at an interval of 12 weeks developed significantly increased antibody responses compared with animals receiving immunizations 4 weeks apart (P = 0·046). The ability to deliver TSOL18 vaccination effectively where the revaccination schedule can be delayed for up to 12–16 weeks in pigs increases the options available for designing T. solium control interventions that incorporate TSOL18 vaccination.
Harvesting solar energy, is only one of the incentives of incorporating photosynthetic proteins in electrochemical devices. Understanding the interface of photosynthetic protein complexes and organic\inorganic underlying electrodes can give rise to development of new generation of nano-bioelectronics for other applications such as sensing, as well. Previous approaches in fabricating photosynthetic bio-hybrid electrochemical solar cells were mainly based on metallic electrodes with protein complexes attached, either directly or through linker molecules. Due to the energy band structure in semiconductors, they potentially can be useful for selective charge transfer in an electrochemical device. In the current study, a two terminal sealed bio-hybrid solar cell device was fabricated comprising of hydrothermally grown ZnO nanowires on fluorine doped tin oxide (FTO) glass working electrode, a Pt counter electrode, and methyl viologen (MV) as a single diffusible redox mediator. The ZnO working electrode was initially characterized using scanning electron microscopy (XRD) and X-ray diffraction (XRD). A solution of dimeric Rhodobacter sphaeroides – light harvesting 1 (RC-LH1) core complexes and redox electrolyte was injected into the cavity between working and counter electrodes. Such structure resulted in ∼0.64 µA.cm-2 photocurrent density and ∼0.24 V open circuit potential difference in the dark and under illumination. Additionally, the device stability tests demonstrated that the current response of such devices remained unchanged after 33 hours storage in the dark.
Psychomotor slowing has been documented in depression. The digital Clock Drawing Test (dCDT) provides: (i) a novel technique to assess both cognitive and motor aspects of psychomotor speed within the same task and (ii) the potential to uncover subtleties of behavior not previously detected with non-digitized modes of data collection. Using digitized pen technology in 106 participants grouped by Age (younger/older) and Affect (euthymic/unmedicated depressed), we recorded cognitive and motor output by capturing how the clock is drawn rather than focusing on the final product. We divided time to completion (TTC) for Command and Copy conditions of the dCDT into metrics of percent of drawing (%Ink) versus non-drawing (%Think) time. We also obtained composite Z-scores of cognition, including attention/information processing (AIP), to explore associations of %Ink and %Think times to cognitive and motor performance. Despite equivalent TTC, %Ink and %Think Command times (Copy n.s.) were significant (AgeXAffect interaction: p=.03)—younger depressed spent a smaller proportion of time drawing relative to thinking compared to the older depressed group. Command %Think time negatively correlated with AIP in the older depressed group (r=−.46; p=.02). Copy %Think time negatively correlated with AIP in the younger depressed (r=−.47; p=.03) and older euthymic groups (r=−.51; p=.01). The dCDT differentiated aspects of psychomotor slowing in depression regardless of age, while dCDT/cognitive associates for younger adults with depression mimicked patterns of older euthymics. (JINS, 2014, 20, 1–9)
In this paper, we propose a new design of metamaterial and electromagnetic bandgap (EBG) structure based on double layers of metallic grids. Using finite integration technique, the electromagnetic properties of the grid structure have been investigated and this structure has been employed to enhance the performance of a patch antenna working at 11 GHz. The surface waves in the substrate of antenna have been suppressed by EBG behavior of the grid when used as a substrate, and it improves its gain to 9.21 dB from 5.64 dB. When this structure is also used as superstrate of the antenna, the gain up to 13 dB has been achieved due to its metamaterial behavior. Congregation effect of metamaterial provides a huge improvement in the directionality of the antenna and its half power beam width (HPBW) has been improved to 32.7° and 31.5° from 108.3° and 93.5° in E-and H-planes, respectively.
In this contribution, we report the synthesis and characterization of NixFe3-xO4 and CoxFe3-xO4 redox nanomaterials using sol-gel method. These materials will be used to produce solar fuels such as H2 or syngas from H2O and/or CO2 via solar thermochemical cycles (STCs). For the sol-gel synthesis of ferrites, the Ni, Co, Fe precursor salts were dissolved in ethanol and propylene oxide (PO) was added dropwise to the well mixed solution as a gelation agent to achieve gel formation. Freshly synthesized gels were aged, dried, and calcined by heating them to 600°C in air. The calcined powders were characterized by powder x-ray diffractometer (XRD), BET surface area, as well as scanning (SEM) and transmission (TEM) electron microscopy. Their suitability to be used in STCs for the production of solar fuels was assessed by performing several reduction/re-oxidation cycles using a thermogravimetric analyzer (TGA).
A retrospective study was undertaken to analyse set-up variations in patients being treated with post-operative radiation therapy for carcinoma of gall bladder by image-guided radiotherapy (IGRT) using cone-beam computed tomography (CBCT) scans and paired kilovoltage beam portals (kVps).
Materials and methods
Three consecutive patients receiving post-operative radiation therapy for carcinoma of gall bladder were studied. A total of 32 imaging studies were performed. The immobilisation system was an all-in-one system along with a thermoplastic mask, with knees either resting on the knee rest or in a vacuum cushion. The CBCT scans and kVps were reviewed in an off-line mode. The surrogate markers used for matching during co-registration were 12th rib, coeliac trunk, vertebral bodies and canal. Individual readings were used to calculate mean shifts (m); the mean of these means (M) was calculated to arrive at the systematic error in each direction and its standard deviation (Σ) was calculated. The margins for set-up error (SM) were then calculated.
There were a total of 32 readings of which 21 were CBCTs and 11 were kVps. The mean shifts in each direction for each patient were 0·06, 0·25 and 0·15 cm in vertical, longitudinal and lateral directions, respectively. The resultant planning target volume margins calculated were 0·24, 0·9 and 0·47 cm in vertical, longitudinal and lateral directions.
IGRT for upper abdominal malignancies using CBCT and kVps is a useful method to keep the margins for set-up error low. The use of surrogates for matching should be relevant to the target volume. Good immobilisation system helps in keeping the margins low.