With numerous pharmacological and biological functions bio-flavonoids gain appreciable attention in diabetes and other therapeutic research. Among several beneficial flavonoids quercetin exhibits ...impressive hypoglycemic effects, with significant improvement, stabilization of long sustaining insulin secretion and regeneration of human islets in the pancreas without producing serious health hazards. However, in oral delivery poor solubility, stability in biological milieu, low permeation, short biological half-life, and insignificant bioavailability limit its wide application in anti diabetic research. Over the last few decades polymeric carrier systems have been widely studied for improvement of quercetin bioavailability. Natural polymers are more preferred in this regard as they possess several favourable properties like biocompatibility, biodegradability, mucoadhesiveness, non-immunogenicity and non-toxicity. This review focuses on quercetin in anti-diabetic research and the progress in the synthesis of polymer-based formulations for efficient quercetin delivery, with an emphasis on producing an improved biological efficacy of the flavonoid. Diabetic complications, probable mechanisms of quercetin absorption, regulation and anti diabetic effects, obstacles to produce desired bio-efficacy and possible remedies are also brought into focus. To overcome these barriers encapsulation of quercetin within various safe polymeric vehicles are discussed. Further, this review sheds light on enhancing the efficacy of quercetin in novel ways for successful diabetes treatment and others.
With numerous pharmacological and biological functions bio-flavonoids gain appreciable attention in diabetes and other therapeutic research.
•Preparation of pH sensitive succinyl chitosan/alginate core-shell nanoparticles.•Nanoparticles used diabetes treatment show 90nm size with −24mV zeta potential.•∼95% quercetin encapsulation with ...self-sustained release following non-fickian trend.•Pronounced hypoglycaemic effect and maintenance of glucose homeostasis in diabetics.•Safe, non-toxic, polymeric drug carriers for diabetes treatment.
The study aims for development of an efficient polymeric carrier for evaluating pharmaceutical potentialities in modulating the drug profile of quercetin (QUE) in anti-diabetic research. Alginate and succinyl chitosan are focused in this investigation for encapsulating quercetin into core-shell nanoparticles through ionic cross linking. The FT-IR, XRD, NMR, SEM, TEM, drug entrapment and loading efficiency are commenced to examine the efficacy of the prepared nanoparticles in successful quercetin delivery. Obtained results showed the minimum particle size of ∼91.58nm and ∼95% quercetin encapsulation efficiently of the particles with significant pH sensitivity. Kinetics of drug release suggested self-sustained QUE release following the non-fickian trend. A pronounced hypoglycaemic effect and efficient maintenance of glucose homeostasis was evident in diabetic rat after peroral delivery of these quercetin nanoparticles in comparison to free oral quercetin. This suggests the fabrication of an efficient carrier of oral quercetin for diabetes treatment.
One new homologous series of mesogenic compounds containing imine (-CH = N-) and ester (-COO-) linkages as well as lateral thiol (−SH) group and terminal alkoxy chain was synthezised. Molecules in ...the present work was convinced with respective right structure confirmed with FT-IR,
1
H-NMR and
13
C-NMR spectroscopy. Thermotropic properties of the compounds were investigated on a hot-stage plate of a polarising optical microscope and further by differential scanning calorimetry. All the compounds of the series exhibited excellent liquid crystalline nature. Structure-property relationships, the influence of different flexible spacers and the mesophase ranges were studied. Computational studies and the electron density method was performed with B3LYP method for all molecular structures in present work. The mesophase ranges were found to be dependent on the length and flexibility of the alkoxy chain, as well as the presence of the lateral thiol group. The comparative study of the present series with the geometrically related series provided valuable insights into the effect of molecular shape on the mesomorphic properties.
In the current study, two new unsymmetrical liquid crystalline homologous series of dimers with a rigid biphenyl core were synthesised using an ether-linking group. Several spectroscopic methods, ...including FT-IR,
1
H-NMR,
13
C-NMR, elemental analysis and mass spectrometry, were used to describe the synthesized dimers. Differential scanning calorimetry (DSC) and polarised optical microscopy (POM) were used to assess their mesomorphic properties. The results showed that the number of methylene spacers significantly affected the thermal properties of the synthesized dimers. To ascertain photophysical behaviour, UV-Visible spectroscopy was employed. Nematic-type mesophase patterns with good mesophase range and thermal stability were seen in both series. Dimers with flexible spacers (
n
= 2, 4, 6) had the best liquid crystalline nature out of all the dimers. The relationships between structure and its mesogenic property, the effects of various flexible spacers, the mesophase ranges, and the photo-isomerization of liquid crystalline dimers were all investigated. DFT Studies were carried out to gain a better understanding of structural features.
Campylobacter is an emerging zoonotic bacterial threat in the poultry industry. Most of the human cases of campylobacteriosis recorded have revealed their poultry origins. Various control measures ...have been employed both at the farm and processing levels to combat with it. The antibiotic treatment, phage therapy, competitive exclusion, and vaccination have been adapted at the farm level to reduce colonization of Campylobacter in poultry gut. While prevention of intestinal spillage, scheduled slaughter, logistic slaughter, chemical decontamination of carcasses are recommended to reduce contamination during processing. The postharvest interventions such as heat treatment, freezing, irradiation of contaminated carcass can effectively reduce Campylobacter contamination. Thus, integrated approaches are required to tackle infection of Campylobacter in humans.
In this paper, we present the preliminary results of a new global three‐dimensional (3‐D) ionospheric model developed using artificial neural networks (ANNs) by assimilating long‐term ionospheric ...observations from nearly two decades of ground‐based Digisonde, satellite‐based topside sounders, and global positioning system‐radio occultation measurements. The present 3‐D model is named ANN‐based global 3‐D ionospheric model (ANNIM‐3D), which is the extension of previous work on the ANN‐based two‐dimensional ionospheric model by Sai Gowtam and Tulasi Ram (2017a, https://doi.org/10.1002/2017JA024795) and Tulasi Ram et al. (2018, https://doi.org/10.1029/2018JA025559). The vertical electron density profiles derived from ANNIM‐3D model are found to be consistent with the ground‐based incoherent scatter radar observations at Jicamarca and Millstone Hill. The model results have been thoroughly validated and found in good agreement with the ground‐based Digisonde and satellite in situ observations at different altitudes. This model successfully reproduces the large‐scale ionospheric phenomena like diurnal and seasonal variations of equatorial ionization anomaly and its hemispheric asymmetries, ionospheric annual anomaly, and the main ionospheric trough. Also, the present model has predicted the ionospheric response that is consistent with the neutral composition changes and meridional wind circulations during disturbed geomagnetic activity periods. Finally, the merits and limitations of this model and the scope for the potential improvements have been discussed.
Key Points
A new artificial neural network‐based 3‐D ionospheric model (ANNIM‐3D) using nearly two decades of global ionospheric data is presented
The ANNIM‐3D predictions are consistent with the ground‐based Digisonde, incoherent scatter radar, and satellite in situ observations
The ANNIM‐3D can successfully reproduce EIA, annual anomaly, main ionospheric trough, and ionospheric response to geomagnetic activity
In the present paper, we calculated the elastic, mechanical, and thermophysical properties of NbN/MgO(001) layers in the temperature range 600–900°C using higher order elastic constants. With two ...fundamental factors, nearest-neighbour distance as well as hardness parameter, the second and third order elastic constants are estimated using the Born–Mayer potential approaches. The computed values of second order elastic constant are used to calculate Young modulus, thermal conductivity, Zener anisotropy, bulk modulus, thermal energy density, shear modulus as well as Poisson ratio in order to assess the thermal and mechanical properties of NbN/MgO(001) layers. Additionally, the second order elastic constant is also used to calculate the wave velocities for shear and longitudinal modes of propagation along crystalline orientations 100, 110, 111. Temperature dependent Debye average velocity, hardness, and ultrasonic Grüneisen parameters are evaluated. The fracture/toughness
B
/
G
ratio in the current investigation is more than 1.75, indicating that the NbN/MgO(001) nanostructured layer is ductile in nature in this temperature range. The selected materials are fully satisfying the Born mechanical stability requirement. The time required for thermal relaxation is calculated and how ultrasonic waves are attenuated by thermo-elastic relaxation and phonon–phonon interaction mechanisms. The findings with other well-known physical features are helpful for industrial applications.
The Lennard-Jones potential approach is used to investigate the effect of pressure on the ultrasonic and elastic properties of the rare-earth ternary TbNiAl intermetallic compound. The second- and ...third-order elastic constants of TbNiAl are considered using the potential model. The pressure-dependent higher-order elastic constants are studied, and it is observed that the elastic constants of the TbNiAl compound increased monotonously with pressure. The hexagonal TbNiAl compound is mechanically stable up to the pressure 20 GPa according to the Born elastic stability criteria. The Voigt–Reuss–Hill approach is used to compute such elastic parameters as Young’s modulus, bulk modulus, Poisson’s ratio, and shear modulus in the pressure range 0–45 GPa. Hardness, melting temperature, and anisotropy are also determined for the intermetallic TbNiAl compound. The pressure-dependent velocities and attenuation of ultrasonic waves in this ternary compound are evaluated. The computation results are also satisfactory in estimating the Debye temperature and thermal conductivity
K
min
under different pressure. It is observed that TbNiAl has a significant anisotropy at zero pressure, which becomes stronger as the pressure increased. This ternary compound behaves as its purest form at higher pressure and is more ductile, which is demonstrated by the minimum attenuation.
Let
L
1
(
r
,
f
)
and
Δ
(
r
,
f
)
denote, respectively, the integral means and the area of the image of the subdisk
D
r
:
=
{
z
:
z
∈
C
and
|
z
|
<
r
;
0
≦
r
<
1
}
of a function
f
, which is analytic ...in
D
. For
j
=
0
,
1
,
2
,
…
,
k
-
1
(
k
=
1
,
2
,
3
,
…
)
,
A
∈
C
;
-
1
≦
B
≦
0
with
A
≠
B
,
we introduce the family of the Janowski type (
j
,
k
)-symmetric starlike functions, which is denoted by
ST
j
,
k
(
A
,
B
)
.
Here, in this article, we first derive the bounds on
L
1
(
r
,
f
j
,
k
)
for every
f
j
,
k
∈
ST
j
,
k
(
A
,
B
)
.
The necessary coefficient condition for functions in the class
ST
j
,
k
(
A
,
B
)
is then presented. Our investigation leads us to get the sharp bounds on Yamashita’s functional of the form
Δ
r
,
z
f
j
,
k
.
Finally, we provide the sharp estimate of the
n
th logarithmic coefficient.
Texturing the front surface of thin film photovoltaic cells with ordered or disordered arrangements of subwavelength structures is beneficial in terms of efficient light harvesting as well as ...efficient carrier extraction. Previous studies demonstrated efficient broadband absorption of solar radiation with surface arrays of subwavelength inverted cones (light funnels - LFs). In the current work, we use three-dimensional finite-difference time-domain electromagnetic calculations as well as three-dimensional device calculations to examine carrier extraction from photovoltaic cells that are composed of LF arrays on top of underlying substrates. For the selected geometry under examination, we show a broadband absorption enhancement of 14% for the LF photovoltaic cell compared with a cell based on the respective optically optimized nanopillar arrays. However, we show that the nominal power conversion efficiency is 60% higher in the LF cell which is due to the enhancement of both open-circuit voltage and short-circuit current. The higher open-circuit voltage in the LF cell is due to the higher injection of photocarriers, and the higher short-circuit current is a result of the unique LF geometry that supports efficient carrier extraction due to the naturally occurring gradients of the quasi-Fermi levels and minority carrier conductivity that allow for enhanced contact selectivity. We believe that this work paves the way towards a new approach for carrier collection in photonic devices for energy applications.
Texturing the front surface of thin film photovoltaic cells with ordered or disordered arrangements of subwavelength structures is beneficial in terms of efficient light harvesting as well as efficient carrier extraction.
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