•YSZ films are deposited by RF plasma MOCVD using Zr(tod)4 and Y(tod)3 precursors.•Films are deposited under the influence of RF self-bias on the substrates.•Films are characterized by different ...techniques.•Films properties are dependent on yttria content and film structure.
Yttria stabilized zirconia thin films have been deposited by RF plasma enhanced MOCVD technique on silicon substrates at substrate temperature of 400°C. Plasma of precursor vapors of (2,7,7-trimethyl-3,5-octanedionate) yttrium (known as Y(tod)3), (2,7,7-trimethyl-3,5-octanedionate) zirconium (known as Zr(tod)4), oxygen and argon gases is used for deposition. To the best of our knowledge, plasma assisted MOCVD of YSZ films using octanediaonate precursors have not been reported in the literature so far. The deposited films have been characterized by GIXRD, FTIR, XPS, FESEM, AFM, XANES, EXAFS, EDAX and spectroscopic ellipsometry. Thickness of the films has been measured by stylus profilometer while tribological property measurement has been done to study mechanical behavior of the coatings. Characterization by different techniques indicates that properties of the films are dependent on the yttria content as well as on the structure of the films.
The modular synthesis of a library containing seven self-assembling amphiphilic Janus dendrimers is reported. Three of these molecules contain environmentally friendly chiral-racemic fluorinated ...dendrons in their hydrophobic part (R F ), one contains achiral hydrogenated dendrons (R H ), while one denoted hybrid Janus dendrimer, contains a combination of chiral-racemic fluorinated and achiral hydrogenated dendrons (R HF ) in its hydrophobic part. Two Janus dendrimers contain either chiral-racemic fluorinated dendrons and a green fluorescent dye conjugated to its hydrophilic part (R F -NBD) or achiral hydrogenated and a red fluorescent dye in its hydrophilic part (R H -RhB). These R F , R H , and R HF Janus dendrimers self-assembled into unilamellar or onion-like soft vesicular dendrimersomes (DSs), with similar thicknesses to biological membranes by simple injection from ethanol solution into water or buffer. Since R F and R H dendrons are not miscible, R F -NBD and R H -RhB were employed to investigate by fluorescence microscopy the self-sorting and coassembly of R F and R H as well as of phospholipids into hybrid DSs mediated by the hybrid hydrogenated-fluorinated R HF Janus dendrimer. The hybrid R HF Janus dendrimer coassembled with both R F and R H . Three-component hybrid DSs containing R H , R F , and R HF were formed when the proportion of R HF was higher than 40%. With low concentration of R HF and in its absence, R H and R F self-sorted into individual R H or R F DSs. Phospholipids were also coassembled with hybrid R HF Janus dendrimers. The simple synthesis and self-assembly of DSs and hybrid DSs, their similar thickness with biological membranes and their imaging by fluorescence and 19F-MRI make them important tools for synthetic biology.
We report cumulants of the proton multiplicity distribution from dedicated fixed-target Au+Au collisions at sqrts_{NN}=3.0 GeV, measured by the STAR experiment in the kinematic acceptance of ...rapidity (y) and transverse momentum (p_{T}) within -0.5<y<0 and 0.4<p_{T}<2.0 GeV/c. In the most central 0%-5% collisions, a proton cumulant ratio is measured to be C_{4}/C_{2}=-0.85±0.09 (stat)±0.82 (syst), which is 2σ below the Poisson baseline with respect to both the statistical and systematic uncertainties. The hadronic transport UrQMD model reproduces our C_{4}/C_{2} in the measured acceptance. Compared to higher energy results and the transport model calculations, the suppression in C_{4}/C_{2} is consistent with fluctuations driven by baryon number conservation and indicates an energy regime dominated by hadronic interactions. These data imply that the QCD critical region, if created in heavy-ion collisions, could only exist at energies higher than 3 GeV.
In order to evaluate internal exposure to radon and thoron, concentrations for radon, thoron, and thoron progeny were measured for 259 dwellings located in high background radiation areas (HBRAs, ...outdoor external dose: 3-5 mGy y
) and low background radiation areas (control areas, outdoor external dose: 1 mGy y
) in Karunagappally Taluk, Kerala, India. The measurements were conducted using passive-type radon-thoron detectors and thoron progeny detectors over two six-month measurement periods from June 2010 to June 2011. The results showed no major differences in radon and thoron progeny concentrations between the HBRAs and the control areas. The geometric mean of the annual effective dose due to radon and thoron was calculated as 0.10 and 0.44 mSv, respectively. The doses were small, but not negligible compared with the external dose in the two areas.
In this present research, the effects of grain refiner (Ti-B) and eutectic modifier (Sr) on the microstructural feature, casting defects, and mechanical properties of Al-7Si alloys are studied. ...Addition of grain refiner (0.1 wt.% Ti) into Al-7Si melt can significantly change the morphology of dendritic α-Al phase to finer equiaxed grains and eutectic modifier (0.05 wt.% Sr) changes the plate-type eutectic Si particles into fine fibrous-/spherical-type particles leads to improve mechanical properties. AFM analysis reveals that combined effect of grain refiner and eutectic modifier on Al-7Si alloy can easily reduce the surface roughness and casting defects such as porosity and shrinkage. The formation of TiAl
3
and Ti
7
Al
5
Si
14
precipitates refines the α-Al grains, and SrSi
2
Al
2
precipitate modifies eutectic Si particles during solidification. Both the precipitates are identified by XRD and TEM analysis. The ultimate tensile strength (UTS, MPa), yield strength (YS, MPa), and elongation to fracture (El, %) of developed AS4 alloy are 164, 91 MPa, and 30%, respectively, which are significantly higher than those of developed as-cast AS1 alloy (UTS: 117 MPa, YS: 78 MPa, and El: 16%). The developed microstructural features are correlated with mechanical properties of the alloy by using a liner equation. This correlation suggests that SDAS and morphology of eutectic Si particles play a vital role in the enhancement of mechanical properties (UTS, MPa) of the developed alloys. The grain-refined and eutectic modified alloy exhibit more dimple formation on the fracture surface indicating more ductility.
Abstract
Background
Cinnamomum cassia
bark is the outer skin of an evergreen tall tree belonging to the family Lauraceae containing several active components such as essential oils (cinnamic aldehyde ...and cinnamyl aldehyde), tannin, mucus and carbohydrate. They have various biological functions including anti-oxidant, anti-microbial, anti-inflammation, anti-diabetic and anti-tumor activity. Previously, we have reported that anti-cancer effect of cinnamon extracts is associated with modulation of angiogenesis and effector function of CD8
+
T cells. In this study, we further identified that anti-tumor effect of cinnamon extracts is also link with enhanced pro-apoptotic activity by inhibiting the activities NFκB and AP1 in mouse melanoma model.
Methods
Water soluble cinnamon extract was obtained and quality of cinnamon extract was evaluated by HPLC (High Performance Liquid Chromatography) analysis. In this study, we tested anti-tumor activity and elucidated action mechanism of cinnamon extract using various types of tumor cell lines including lymphoma, melanoma, cervix cancer and colorectal cancer
in vitro
and
in vivo
mouse melanoma model.
Results
Cinnamon extract strongly inhibited tumor cell proliferation
in vitro
and induced active cell death of tumor cells by up-regulating pro-apoptotic molecules while inhibiting NFκB and AP1 activity and their target genes such as
Bcl-2
,
BcL-xL
and
survivin
. Oral administration of cinnamon extract in melanoma transplantation model significantly inhibited tumor growth with the same mechanism of action observed
in vitro
.
Conclusion
Our study suggests that anti-tumor effect of cinnamon extracts is directly linked with enhanced pro-apoptotic activity and inhibition of NFκB and AP1 activities and their target genes
in vitro
and
in vivo
mouse melanoma model. Hence, further elucidation of active components of cinnamon extract could lead to development of potent anti-tumor agent or complementary and alternative medicine for the treatment of diverse cancers.
In this current study, comprehensive investigations were carried out to examine the pyroelectric energy storage, electrocaloric performance, and temperature-sensitive scaling behavior of ...Ba0.85Ca0.15Zr0.10Ti0.9O3 ceramics synthesized by mixed oxide route. Tetragonal and orthorhombic symmetries were concurrently present with the presence of a single perovskite material under ambient conditions, according to X-ray diffraction (XRD) and Rietveld refinement investigations. The scanning electron micrograph reveals distinct, pore-free grain structures. The dielectric performance shows a temperature-dependent characteristic with a diffuse phase transition. The temperature-sensitive behavior of ferroelectric hysteresis was analyzed with a variety of applied electric fields. The pyroelectric energy storage capabilities were assessed using the Olsen cycle for calculation. Furthermore, figures of merit (FoMs) for pyroelectric properties, including responsivity (Fv), current responsivity (Fi), energy harvesting (Fe), new energy harvesting (Fe*), and detectivity (Fd), were computed. An indirect method based on the thermodynamic Maxwell's relation was employed to analyze the changes in adiabatic temperature, isothermal entropy, and electrocaloric strength. The scaling relationships for ferroelectric hysteresis, specifically about the coercive field (EC), remnant polarization (Pr), and hysteresis area ( ), were methodically explored across varying temperatures (T). The power-law temperature exponents were found for all the associated hysteresis parameters.
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Introduction: COVID-19 has affected the quality of life of all age groups. Medical education during the pandemic shifted to online mode due to lockdown restrictions. The stress felt by medical ...students during the pandemic has been studied less. The current study aimed to assessed the stressors and de-stressors for undergraduate medical students during the COVID-19 pandemic. Materials and methods: A cross-sectional online survey was conducted for the undergraduate medical students of a tertiary care institute of eastern India. A total of 307 medical students were included in the study by convenient and snowball sampling. A self-designed semi-structural questionnaire was created as a Google form and circulated among the students between September and October 2020. A combination of purposive and snowball sampling was adopted. Responses regarding stressors and de-stressors were recorded on a Likert scale. Data analysis was performed using Statistical Package for Social Sciences (SPSS) version 22. Categorical variables were presented as percentages and descriptive statistics were performed. Results: A total of 307 students responded and 64.5% of them were men and 35.5% were women. 47.6% of the students experienced stress due to changes brought about by COVID-19. Risk of parents getting infection (63.2%), fear of not easily returning home (53.1%), lack of clinical exposure (52.7%), and financial impact (47.9%) were the major stressors perceived by the students. Connecting with family and friends through social media (47.5%), gaming (45.0%), online streaming platform (51.2%), spending time with family members (54.4%) were the coping strategies adopted by these students. Conclusion: Higher level of psychological stress perceived by the undergraduate students needs psychological intervention. Academic revamp and adaptation of coping strategies are required for the medical under-graduates.
The majority of presently exploitable marine methane hydrate reservoirs are likely to host hydrate in disseminated form in coarse grain sediments. For hydrate concentrations below 25–40%, ...disseminated or pore‐filling hydrate does not increase elastic frame moduli, thus making impotent traditional seismic velocity‐based methods. Here, we present a theoretical model to calculate frequency‐dependent P and S wave velocity and attenuation of an effective porous medium composed of solid mineral grains, methane hydrate, methane gas, and water. The model considers elastic wave energy losses caused by local viscous flow both (i) between fluid inclusions in hydrate and pores and (ii) between different aspect ratio pores (created when hydrate grows); the inertial motion of the frame with respect to the pore fluid (Biot's type fluid flow); and gas bubble damping. The sole presence of pore‐filling hydrate in the sediment reduces the available porosity and intrinsic permeability of the sediment affecting Biot's type attenuation at high frequencies. Our model shows that attenuation maxima due to fluid inclusions in hydrate are possible over the entire frequency range of interest to exploration seismology (1–106 Hz), depending on the aspect ratio of the inclusions, whereas maxima due to different aspect ratio pores occur only at sonic to ultrasound frequencies (104–106 Hz). This frequency response imposes further constraints on possible hydrate saturations able to reproduce broadband elastic measurements of velocity and attenuation. Our results provide a physical basis for detecting the presence and amount of pore‐filling hydrate in seafloor sediments using conventional seismic surveys.
Key Points
Pore‐filling hydrate in sediments enhances elastic wave attenuation at 1–1E6 Hz due to increased fluid‐solid contacts and squirt flow
Hydrate‐formed pores of different aspect ratios enhance elastic wave attenuation at 1E4–1E6 Hz and fluid inclusions in hydrate at 1–1E6 Hz
Elastic wave attenuation due to fluid inclusions in hydrate may provide signal contrasts to detect pore‐filling hydrate in seismic surveys
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