Highly oriented thin films of poly2,5-bis(3-tetradecylthiophen-2-yl)thieno3,2-bthiophene (PBTTT) were prepared by friction-transfer technique followed by their characterization using polarized ...absorption spectroscopy, angle-dependent polarized Raman spectroscopy, and X-ray diffraction (XRD) techniques. Orientation in high-molecular-weight (M W) polymers is hampered by chain folding or entanglements, which limit their macromolecular orientation. Interestingly, utilizing high-molecular-weight PBTTT (M W > 50 kDa) and friction-transfer technique, successful fabrication of highly oriented thin films with very high dichroic ratio (∼30) was demonstrated. The role of the substrate’s surface energy and its impact on the field-effect mobility (μ) of the oriented thin films were comprehensively investigated. The influence of annealing the thin films as prepared on the bare and self-assembled monolayer (SAM)-treated SiO2 surfaces exhibiting differential trends of μ was systematically investigated. This was explained by partial and complete conformational transformation of macromolecules on bare and SAM-treated SiO2 surfaces, respectively, after annealing them beyond liquid crystalline phase transition temperature, as revealed by in-plane and out-of-plane XRD results. On bare SiO2, optimum μ up to 0.03 cm2 V–1 s–1 along the backbone orientation was obtained for the thin films annealed to 120 °C; whereas, it reached up to 0.36 cm2 V–1 s–1 on SAM-treated SiO2 after annealing at 200 °C. Finally, a charge transport mechanism was proposed taking evidence from the anisotropic optical and electrical characteristics of the friction-transferred PBTTT films into consideration.
Unavoidable defects in grain boundaries (GBs) are detrimental and critically influence the organometal halide perovskite performance and stability. To address this issue, semiconducting molecules ...have been employed to passivate traps along perovskite GBs. Here, we designed and synthesized three squaraine molecules (SQ) with zwitterionic structure to interact with under-coordinated Pb2+ and passivate Pb–I antisite defects. Density functional theory calculation shows symmetric O atoms could coordinate with perovskite grains simultaneously, resulting in continuous charge distribution at the SQ–perovskite interface. The energetic traps distribution in CH3NH3PbI3 perovskite is influenced significantly by the interaction between SQ and perovskite as analyzed by thermally stimulated current, in which the deep-level defects are considerably reduced due to efficient SQ passivation. In addition, we explore how SQ molecules with different energy offset affect the charge extraction, which is suggested to facilitate exciton separation at the perovskite–SQ interface. These benefits lead to enhanced perovskite efficiency from 15.77 to 18.83% with the fill factor approaching 80%, which is among the highest efficiency reported for MAPbI3 solar cells fabricated in an ambient environment at 60% relative humidity (RH). Considerable retardation of perovskite device degradation was achieved, retaining 90% of initial efficiency when kept 600 h at 60 ± 5% RH.
Abstract The large molecular weight of the macromolecules sets them apart from all other components. This may range from 10 000 to over a million. While the molecular weight of other plant ...metabolites is seldom beyond 1000. Chemically, macromolecules are made up of long chains and little “building pieces,” which are joined covalently in a variety of ways. Biological macromolecules are large, naturally occurring cellular building blocks that play a range of crucial roles in the development and existence of living organisms. Biomacromolecules are essential in the biomedical field and other related professions. They feature a variety of beneficial properties, including excellent biodegradability, suitable mechanical strength, enhanced bioavailability, etc. They also have significant biocompatibility. They display a variety of biological characteristics, such as antimalignant, antidiabetic, antibacterial, antioxidant, and immunomodulatory. The use of essential carbohydrates including alginate, chitosan, pectin, starches, carrageenan, fucoidan, etc. is common in commercial applications. Natural substance‐based pharmacotherapy is now considered to be a highly promising future alternative to conventional medicine. Along with proteins and polynucleotides, polysaccharide is a vital biomacromolecule that has a crucial function in the growth and expansion of living things. A crucial element of higher plants, cell membranes of animal, and cell walls of microbes is polysaccharide. It is intimately tied to physiological processes as well. The importance of polysaccharides as a significant class of bioactive natural compounds has received more attention recently. Numerous studies have shown that natural polysaccharides contain bioactivities, which have led to the use of polysaccharides in the treatment of illness. The many parts of the research findings on the bioactivities of polysaccharides in gastro‐protection are included in this paper.
Peroxyacetyl nitrate (PAN) formed in the atmospheric oxidation of non-methane volatile organic compounds (NMVOCs) is the principal tropospheric reservoir for nitrogen oxide radicals (NO
= NO + NO
). ...PAN enables the transport and release of NO
to the remote troposphere with major implications for the global distributions of ozone and OH, the main tropospheric oxidants. Simulation of PAN is a challenge for global models because of the dependence of PAN on vertical transport as well as complex and uncertain NMVOC sources and chemistry. Here we use an improved representation of NMVOCs in a global 3-D chemical transport model (GEOS-Chem) and show that it can simulate PAN observations from aircraft campaigns worldwide. The immediate carbonyl precursors for PAN formation include acetaldehyde (44% of the global source), methylglyoxal (30 %), acetone (7 %), and a suite of other isoprene and terpene oxidation products (19 %). A diversity of NMVOC emissions is responsible for PAN formation globally including isoprene (37 %) and alkanes (14 %). Anthropogenic sources are dominant in the extratropical Northern Hemisphere outside the growing season. Open fires appear to play little role except at high northern latitudes in spring, although results are very sensitive to plume chemistry and plume rise. Lightning NO
is the dominant contributor to the observed PAN maximum in the free troposphere over the South Atlantic.
Molecularly targeted cancer therapies substantially improve patient outcomes, although the durability of their effectiveness can be limited. Resistance to these therapies is often related to adaptive ...changes in the target oncoprotein which reduce binding affinity. The arsenal of targeted cancer therapies, moreover, lacks coverage of several notorious oncoproteins with challenging features for inhibitor development. Degraders are a relatively new therapeutic modality which deplete the target protein by hijacking the cellular protein destruction machinery. Degraders offer several advantages for cancer therapy including resiliency to acquired mutations in the target protein, enhanced selectivity, lower dosing requirements, and the potential to abrogate oncogenic transcription factors and scaffolding proteins. Herein, we review the development of proteolysis targeting chimeras (PROTACs) for selected cancer therapy targets and their reported biological activities. The medicinal chemistry of PROTAC design has been a challenging area of active research, but the recent advances in the field will usher in an era of rational degrader design.
Aim
The aim of this study was to identify and characterize promising endophytes capable of enhancing the content of root alkaloids ajmalicine and serpentine in low alkaloid yielding genotype of ...Catharanthus roseus cultivar Prabal and the possible mechanisms involved.
Method and Result
Of the four strains isolated from alkaloid‐rich genotype of C. roseus cultivar Dhawal, endophytic strains CATDLF5 (Curvularia sp.) and CATDLF6 (Choanephora infundibulifera) enhanced serpentine content by 211·7–337·6%, while CATDRF2 (Aspergillus japonicus) and CATDS5 (Pseudomonas sp.) increased the content of ajmalicine by 123·4–203·8% in cultivar Prabal. Upregulated expression of key genes, geraniol 10‐hydroxylase, tryptophan decarboxylase and strictosidine synthase involved in terpenoid indole alkaloid (TIA) biosynthetic pathway was observed in endophyte inoculated plants. Upregulated Octadecanoid‐derivative Responsive Catharanthus AP2/ERF domain transcription activators like ORCA3 while, and downregulation of transcriptional repressor, ZCTs (Cys2/His2‐type zinc finger protein family) enhanced the expression of genes for secondary metabolite production in endophyte‐inoculated plants.
Conclusion
The present work concluded that the selected endophytes of C. roseus can enhance the ajmalicine and serpentine contents by modulating the expression of structural and regulatory genes of TIA biosynthetic pathway in root.
Significance and Impact of the Study
Endophytes can play an important role to enhance in planta content of pharmaceutically important alkaloids in C. roseus and can therefore be useful in reducing the cost of production of important alkaloids.
The paper presents the transportation of viscoelastic fluid with fractional Maxwell model by peristalsis through a channel under long wavelength and low Reynolds number approximations. The ...propagation of wall of channel is taken as sinusoidal wave propagation (contraction and relaxation). Homotopy perturbation method (HPM) and Adomian decomposition method (ADM) are used to obtain the analytical approximate solutions of the problem. The expressions of axial velocity, volume flow rate and pressure gradient are obtained. The effects of fractional parameters
(
α
)
, relaxation time
(
λ
1
)
and amplitude
(
ϕ
)
on the pressure difference and friction force across one wavelength are calculated numerically for different particular cases and depicted through graphs.
The Afterglow and Kilonova of the Short GRB 160821B Troja, E.; Castro-Tirado, A. J.; Gonzalez, J Becerra ...
Monthly notices of the Royal Astronomical Society,
08/2019, Letnik:
489, Številka:
2
Journal Article
Recenzirano
Odprti dostop
GRB 160821B is a short duration gamma-ray burst (GRB) detected and localized by the Neil Gehrels Swift Observatory in the outskirts of a spiral galaxy at z = 0.1613, at a projected physical offset of ...16 kpc from the galaxy’s center. We present X-ray, optical/nIR, and radio observations of its counterpart and model them with two distinct components of emission: a standard afterglow, arising from the interaction of the relativistic jet with the surrounding medium, and a kilonova, powered by the radioactive decay of the sub-relativistic ejecta. Broadband modelling of the afterglow data reveals a weak reverse shock propagating backward into the jet, and a likely jet-break at 3.5 d. This is consistent with a structured jet seen slightly off-axis (θview ∼ θcore) while expanding into a low-density medium (n ≈ 10−3 cm−3). Analysis of the kilonova properties suggests a rapid evolution towards red colours, similar toAT2017gfo, and a low-nIR luminosity, possibly due to the presence of a long-lived neutron star. The global properties of the environment, the inferred low mass (Mej <~ 0.006 Msun) and velocities (vej >~ 0.05c) of lanthanide-rich ejecta are consistent with a binary neutron star merger progenitor.
We present two novel matter-wave Sagnac interferometers based on ring-shaped time-averaged adiabatic potentials, where the atoms are put into a superposition of two different spin states and ...manipulated independently using elliptically polarized rf-fields. In the first interferometer the atoms are accelerated by spin-state-dependent forces and then travel around the ring in a matter-wave guide. In the second one the atoms are fully trapped during the entire interferometric sequence and are moved around the ring in two spin-state-dependent 'buckets'. Corrections to the ideal Sagnac phase are investigated for both cases. We experimentally demonstrate the key atom-optical elements of the interferometer such as the independent manipulation of two different spin states in the ring-shaped potentials under identical experimental conditions.
Rare earth group elements have gained the renewed interest in applications of energy storage and conversion. Apparently, supercapacitive performances of electrodes based on yttrium (Y+3) element are ...still left uncovered for exploration as energy storage device. In this study, the binder free yttrium hydroxide (Y(OH)3) electrodes have been prepared through easy, economical and industry applicable successive ion layer adsorption and reaction (SILAR) method. The Y(OH)3 has been deposited over the stainless steel (SS) substrate for 10 (Y_10), 20 (Y_20) and 30 (Y_30) SILAR cycles. The prepared electrodes have been characterized by using X‐ray diffraction (XRD), fourier‐transform infrared spectroscopy (FTIR), high resolution scanning electron microscopy (HRSEM) and transmission electron microscopy (TEM). The electrochemical performances of the prepared electrodes have been studied in presence of 1 M Na2SO4 electrolyte. The Y_20 shows the superior electrochemical performance than others. The highest specific capacity of 237 C g−1 has been observed for Y_20 at 1 mA current rate along with good cycle stability. Thus, by observing our results, one can say that the prepared electrode has a great potential in area of energy harvesting, power back up, portable devices, etc.
Display omitted
•Binder free yttrium hydroxide (Y(OH)3) electrodes have been prepared by SILAR deposition method.•A crystalline nature of deposited electrodes has been observed with mesoporous nanostructures.•The highest specific capacity of 237 C g−1 has been obtained at 1 mA current rate.•The EIS is used to reveal the electrode parameters and the lowest value of Rs is 1.06Ω.
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