A
bstract
We propose a new method for the evaluation of intersection numbers for twisted meromorphic
n
-forms, through Stokes’ theorem in
n
dimensions. It is based on the solution of an
n
-th order ...partial differential equation and on the evaluation of multivariate residues. We also present an algebraic expression for the contribution from each multivariate residue. We illustrate our approach with a number of simple examples from mathematics and physics.
A
bstract
We present a detailed description of the recent idea for a direct decomposition of Feynman integrals onto a basis of master integrals by projections, as well as a direct derivation of the ...differential equations satisfied by the master integrals, employing multivariate intersection numbers. We discuss a recursive algorithm for the computation of multivariate intersection numbers, and provide three different approaches for a direct decomposition of Feynman integrals, which we dub the
straight decomposition
, the
bottom-up decomposition
, and the
top-down decomposition
. These algorithms exploit the unitarity structure of Feynman integrals by computing intersection numbers supported on cuts, in various orders, thus showing the synthesis of the intersection-theory concepts with unitarity-based methods and integrand decomposition. We perform explicit computations to exemplify all of these approaches applied to Feynman integrals, paving a way towards potential applications to generic multi-loop integrals.
The use of polymer gels for the removal of toxic chemicals from wastewater is an important area in terms of both academic and industrial research. This work presents a simple approach to the ...fabrication of chemically cross-linked cationic hydrogel adsorbents using designed ionic liquid-based cross-linkers and their successful use in the removal of organic dyes. Two different ionic liquid cross-linkers, VIm-4VBCCl (ILA)/DMAEMA-4VBCCl (ILB), are synthesized by the simple nucleophilic substitution reaction of 4-vinylbenzyl chloride (4VBC) separately with 1-vinylimidazole (VIm) and 2-(dimethylamino)ethyl methacrylate (DMAEMA). Cross-linked poly(acrylamide) (CPAam) and poly(2-hydroxyethyl methacrylate) (CPHEMA) hydrogels are then prepared from the corresponding monomers and as-synthesized cross-linkers (ILA and ILB) by free radical polymerization in the presence of a redox initiator combining ammonium persulfate (APS) and N,N,N′,N′-tetramethylethylenediamine (TEMED). The dried CPAam and CPHEMA xerogels exhibit macroporous morphology and high thermal stability. The hydrogel samples exhibit high swelling behavior, and the diffusion of water molecules into the hydrogels follows pseudo-Fickian kinetics. The cationic cross-linking sites in the hydrogel networks allow preferable binding with anionic dyes, and these dye uptake capacities are determined using different model anionic dyes via UV–vis spectroscopy. The dye adsorption onto these hydrogels follows a pseudo-second-order kinetic model. The adsorption mechanism is also analyzed by employing intraparticle diffusion and Boyd kinetic models. The relationship between the maximum equilibrium adsorption capacity (q m) of the hydrogels for eosin B (EB) dye and the equilibrium EB concentration can be better described by Langmuir and Freundlich isotherm models, and the estimated q m using the Langmuir isotherm can reach more than 100 mg g–1. The cross-linked hydrogels can be easily regenerated and have a recycling efficiency of >80% for up to three consecutive dye adsorption–desorption cycles, which is promising for their use in wastewater treatment.
Malaria is a devastating infectious disease and significant global health burden caused by the bite of a Plasmodium-infected female Anopheles mosquito. Gut microbiota was recently discovered as a ...risk factor of severe malaria. This review entails the recent advances on the impact of gut microbiota composition on malaria severity and consequence of malaria infection on gut microbiota in mammalian hosts. Additionally, this review provides mechanistic insight into interactions that might occur between gut microbiota and host immunity which in turn can modulate malaria severity. Finally, approaches to modulate gut microbiota composition are discussed. We anticipate this review will facilitate novel hypotheses to move the malaria-gut microbiome field forward.
In this study we have analysed the elemental composition of fine particulate matter (PM
2.5
) to examine the seasonal changes and sources of the elements in Delhi, India from January, 2017 to ...December, 2021. During the entire sampling period, 19 elements (Al, Fe, Ti, Cu, Zn, Cr, Ni, As, Mo, Cl, P, S, K, Pb, Na, Mg, Ca, Mn, and Br) of PM
2.5
were identified by Wavelength Dispersive X-ray Fluorescence Spectrometer. The higher annual mean concentrations of S (2.29 µg m
-3
), Cl (2.26 µg m
-3
), K (2.05 µg m
-3
), Ca (0.96 µg m
-3
) and Fe (0.93 µg m
-3
) were recorded during post-monsoon season followed by Zn > Pb > Al > Na > Cu > Ti > As > Cr > Mo > Br > Mg > Ni > Mn > and P. The annual mean concentrations of elemental composition of PM
2.5
accounted for 10% of PM
2.5
(pooled estimate of 5 year). Principal Component Analysis (PCA) identified the five main sources crustal/soil/road dust, combustion (BB + FFC), vehicular emissions (VE), industrial emissions (IE) and mixed source (Ti, Cr and Mo rich-source) of PM
2.5
in Delhi, India.
In this study, C(sp2)–H borylation of arenes was accomplished by a nickel catalyst, resulting in good yield. Alkyl and alkoxy arenes were successfully functionalized, affording C(sp2)–H borylated ...compounds. It was unraveled that the well-defined abnormal N-heterocyclic carbene based Ni(II) complex breaks into Ni nanoparticles (Ni-NPs), which act as catalytically active species. A series of controlled reactions under stoichiometric conditions along with spectroscopic studies and single-crystal X-ray crystallographic study helped us to understand the formation of Ni-NPs along with formation of a boron(III) compound during this reaction.
Reprogramming somatic cells to induced pluripotent stem cells (iPSCs) resets their identity back to an embryonic age and, thus, presents a significant hurdle for modeling late-onset disorders. In ...this study, we describe a strategy for inducing aging-related features in human iPSC-derived lineages and apply it to the modeling of Parkinson’s disease (PD). Our approach involves expression of progerin, a truncated form of lamin A associated with premature aging. We found that expression of progerin in iPSC-derived fibroblasts and neurons induces multiple aging-related markers and characteristics, including dopamine-specific phenotypes such as neuromelanin accumulation. Induced aging in PD iPSC-derived dopamine neurons revealed disease phenotypes that require both aging and genetic susceptibility, such as pronounced dendrite degeneration, progressive loss of tyrosine hydroxylase (TH) expression, and enlarged mitochondria or Lewy-body-precursor inclusions. Thus, our study suggests that progerin-induced aging can be used to reveal late-onset age-related disease features in hiPSC-based disease models.
Display omitted
•Reprogramming rejuvenates old donor fibroblasts by erasing age-related markers•Differentiation of old donor iPSCs is not sufficient to trigger memory of age•Progerin induces age-associated phenotypes in iPSC-derived fibroblasts and neurons•Progerin reveals late-onset disease phenotypes in iPSC-based models of genetic PD
The induction of aging-related features in human iPS-derived cells through expression of progerin addresses one of the major limitations of human iPS-based disease modeling and enables analysis of late-onset phenotypes in conditions such as Parkinson’s disease.
We demonstrate a simple templateless and surfactant-free wet-chemical method of preparing silver (Ag) nanostructures with different dendritic morphologies at room temperature. This has been ...accomplished by aging the aqueous mixture of AgNO3 and citrate salts, carrying different cations for different time periods. Transmission electron microscopic (TEM) and X-ray diffraction (XRD) studies confirmed the formation of single-crystalline dendritic Ag nanostructures. It has been found that the nature and the concentration of citrate salt have a significant effect on the morphology of the formed Ag nanostructures. A possible formation mechanism has also been discussed on the basis of monitoring the surface plasmon resonance properties and TEM images with time during the course of formation of silver dendrites. The formed dendritic silver nanostructures showed excellent catalytic activity in the borohydride reduction of p-nitrophenol to p-aminophenol compared to the spherical silver nanoparticles.
A reliable algorithm based on differential evolution (DE) for solving short-term combined economic emission scheduling of hydrothermal systems with several equality and non-equality constraints is ...presented in this paper. The water transport delay between connected reservoirs is also considered. The problem is formulated considering both cost and emission as competing objectives. Combined economic emission scheduling (CEES) is a bi-objective problem. A price penalty factor approach is utilized here to convert this bi-objective CEES problem into a single objective one. The effect of valve point loading is also taken into account in the present problem formulation. The effectiveness of the proposed method is tested on a sample test system consisting of four cascaded hydro units and three thermal units. The results of the proposed technique based on DE are compared with other population based method. It is found that the results obtained by the proposed technique are superior in terms of fuel cost, emission output. It is also observed that the computation time is considerably reduced by the application of the proposed technique based on differential evolution.
Observation of strong deviation of photoluminescence excitation curve from absorption curve especially at lower wavelength range, below 450 nm in case of small-sized toxic metal free InP-based ...core-alloy-shell quantum dots, hints toward interesting exciton dynamics. Photoluminescence quantum yield (PLQY) has been observed to be dependent on the excitation wavelength. Monitoring the bleach dynamics employing femtosecond ultrafast pump–probe technique, it could be shown that the rise time increases with decrease in pump excitation wavelength from 100 fs for 550 nm excitation to 220 fs for 430 nm pump/excitation. Therefore, exciton cooling takes a longer time for lower wavelength excitation, and thus the exciton becomes more prone to get trapped. About twofold enhancement in magnitude of normalized bleach signal at the band-edge (∼0.1 (for 430 nm excitation) to ∼0.2 (for 550 nm excitation)) following exciton relaxation has been observed. Thus, in comparison to lower wavelength excitation, for near band-edge pump/excitation there is higher probability of radiative exciton recombination, therefore increasing PLQY. Hot exciton trapping dynamics has been noted to be occurring at a time scale ∼750 fs. From ultrasensitive single-particle measurement, magnitudes of power-law exponent for both ON and OFF events remain similar to each other, and the magnitude remains unaltered for different excitation wavelengths (405–568 nm). As long as 100 s ON event could be observed, making this InP-based nontoxic quantum dot (QD) quite suitable for single-particle tracking, etc. Interestingly, ON-event truncation time has been found to increase from 6 to 16 s, and OFF-event truncation time has been found to decrease from 11 to 5.5 s; thereby, exciton detrapping rate/trapping rate increases from 0.5 to nearly 3 on going from 405 to 568 nm excitation. Thus, as the trapping gets suppressed and detrapping gets enhanced, PLQY gets enhanced. The extent of relative decrease of PLQY value with increase in excitation energy above band-edge has been observed to be much more pronounced in CdSe-based CAS QD than InP-based CAS QD.
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