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•A brief discussion on the effect of temperature variation on performance parameters studied.•Provides an idea about appropriate HTLs and ETLs to be used for Sn based ...PSCs.•Comparative study of three different Sn based PSCs are conducted.
The perovskite solar cells (PSCs) have become the fastest-growing photovoltaic (PV) cells to date. Despite its numerous merits, these cells face issues, such as poor stability, toxicity, etc. The issue of toxicity is dealt by using less-toxic substitutes of lead (Pb), such as Tin (Sn). However, the performance attained by Sn-based PSCs still lags behind Pb based PSCs to a great extent. In this work, we discuss some of the desirable electron transport layers (ETLs) and hole transport layers (HTLs) that can be used to fabricate an efficient Sn-based PSC, and report their performance. HTLs, such as “Spiro-OMeTAD”, Graphene, PEDOT:PSS, Cu2O, CuI, CuSCN and ETLs, such as ZnO, TiO2, PCBM are used in this study. We also simulate three different Sn perovskite materials based PSCs, (i) MASnI3 (ii) FASnI3 and (iii) CsSn0.5Ge0.5I3. We study theoretically the performance of the PSCs with various transport layers and absorber layers by varying the temperature from 300 K to 400 K.
Dendrimers are emerging class of nanoparticles used in targeted drug delivery systems. These are radially symmetric molecules with well-defined, homogeneous, and monodisperse structures. Due to the ...nano size, they can easily cross the biological membrane and increase bioavailability. The surface functionalization facilitates targeting of the particular site of action, assists the high drug loading and improves the therapeutic efficiency of the drug. These properties make dendrimers advantageous over conventional drug delivery systems. This article explains the features of dendrimers along with their method of synthesis, such as divergent growth method, convergent growth method, double exponential and mixed method, hyper-core and branched method. Dendrimers are effectively used in anticancer delivery and can be targeted at the site of tumor either by active or passive targeting. There are three mechanisms by which drugs interact with dendrimers, and they are physical encapsulation, electrostatic interaction, chemical conjugation of drug molecules. Drug releases from dendrimer either by in vivo cleavage of the covalent bond between drugdendrimer complexes or by physical changes or stimulus like pH, temperature, etc.
Charge transporting materials are essential for fabricating stable and efficient perovskite solar cells. The high-temperature processing, surface defects, and low mobility are common issues in ...inorganic charge transport materials which can hinder the fabrication of low-cost, efficient, and stable perovskite solar cells. Dopants increase the processing cost of the hole transport materials. Surface defects are observed in the high-temperature processed inorganic electron transport materials. There is a need to develop organic compounds for charge transportation in perovskite solar cells. Herein, the advancements in the organic materials for charge transport in the perovskite solar cells are reviewed. The low-cost processing, better solubility, efficient charge mobility, tunable molecular orbitals, and better stability of organic compounds are some properties for their utilization as charge transport materials in perovskite solar cells. Organic small molecules, polymers, and phthalocyanine compounds can be utilized as dopant-free hole transport materials. Fullerene and non-fullerene derivatives like C60, C70, azaacenes, indacenodithiophene, polymers, and rylene diimides are promising electron transport materials. The functionality, engineering, charge transport properties, and device characteristics of different organic materials are discussed. The review will offer a forecast for improving device stability and efficiency in terms of architecture, engineering, and materials to realize the commercialization of perovskite solar cells soon.
A simplified numerical model has been proposed to optimize the effect of pseudo-homogeneous and bulk electrolyte medium in dye-sensitized solar cells. Firstly, the equations of continuity and ...transport are derived for all charged species namely electrons, iodide ions (
) and tri-iodide ions (
). The cell model compiled of a pseudo-homogeneous medium is the grouping of three layers i.e., nanoporous TiO
2
layer, sensitizer and redox mediator. On the other side is a bulk electrolyte medium in which only ion diffusion takes place. Recombinations at the working electrode and a voltage drop at the counter electrode are incorporated in the present model. Parametric studies were conducted to analyze the length of optimal bulk electrolyte layer and a set of simulations executed by changing the morphology in the range from 0.2 to 1.6 μm and gave the highest at 0.8 μm with current density of 31.7 mA cm
–2
. The higher current density ensures a good efficiency. The length of the bulk electrolyte layer is reduced as far as possible, and the length of the active layer mediated in relation to the recombination rates and diffusion control current with the choice of the redox mediator.
•Theoretical study of ZnO nanostructures in infrared and far-field frequency using Mie theory.•Synthesis and characterization of ZnO and Au-ZnO core–shell nanomaterial.•Light scattering peaks for ZnO ...nanostructures in infrared frequency at optimized particle size.•Enhanced electric and magnetic response of Au-ZnO nanomaterial due to surface plasmon resonance.•Synthesized Au-ZnO nanomaterial as a metamaterial for developing nanophotonic technologies.
The synthesized photoluminescent and highly dielectric ZnO nanostructures are theoretically investigated as the metamaterial. Herein, the electric and magnetic responses of the ZnO nanomaterial are enhanced by introducing gold into ZnO to form Au-ZnO core–shell nanomaterial. The ZnO nanostructures are studied by optimizing their particle size in the near-infrared and far-field frequency region using Mie theory. The intense light scattering peaks with a peak shift for the Au-ZnO core–shell nanomaterial at the optimized particle size and particular wavelength in the near-infrared region are observed. A strong electric and magnetic pattern for the Au-ZnO core–shell nanomaterial is observed in the near-infrared and far-field frequency region as compared to the ZnO nanoparticles due to the surface plasmon property of the gold. The results pave the way for the design of complex dielectric materials for different optical applications through metamaterial technologies.
With the increasing use of Open Source Software (OSS) in high speed networking, parallel processing and distributed computing, OSS has emerged as mainstream in the last decade and is now being ...broadly accepted even by the traditional proprietary software development companies. The major advantages of OSS over traditional software development are less development cost, availability of source code, quality and security. Software reliability—an important attribute of software quality, is defined as the probability that a software will operate free of failures or breakdown for a specified time under specified conditions (IEEE Std. 1633-2016). Investigation of Software reliability with the help of software reliability models (SRM) undertakes the estimation and prediction of the failure phenomenon of a software. In this paper we have investigated whether Non-homogeneous Poisson process (NHPP) based software reliability models fit in the big data open source software fault/bug data. We have extracted real and latest bug/fault data of Hadoop and Spark–open source big data applications, from bug tracking/management tool Jira. For this purpose, we have also compared these models on different goodness-of-fit and prediction criteria based on collected failure data to ascertain whether a best fitted model can also be a best predictor. It is found that the best model fitting the failure data is not a best predictor model.
Abstract
The incidence of a penetrating brain injury due to a pressure cooker blast is quite rare. We are presenting this case of a 24-year-old female who sustained anterior skull base injury, with ...the nozzle of the pressure cooker penetrating through left orbit on account of the blast. A combined multidisciplinary approach was utilized and the patient recovered uneventfully.
Neurodegenerative disorders (NDDs) are caused by progressive loss of functional neurons following the aggregation and fibrillation of proteins in the central nervous system. The incidence rate ...continues to rise alarmingly worldwide, particularly in aged population, and the success of treatment remains limited to symptomatic relief. Graphene nanomaterials (GNs) have attracted immense interest on the account of their unique physicochemical and optoelectronic properties. The research over the past two decades has recognized their ability to interact with aggregation-prone neuronal proteins, regulate autophagy and modulate the electrophysiology of neuronal cells. Graphene can prevent the formation of higher order protein aggregates and facilitate the clearance of such deposits. In this review, after highlighting the role of protein fibrillation in neurodegeneration, we have discussed how GN-protein interactions can be exploited for preventing neurodegeneration. A comprehensive understanding of such interactions would contribute to the exploration of novel modalities for controlling neurodegenerative processes.
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•Neurodegeneration occurs following misfolding, aggregation and fibrillation of proteins.•The efficacy of current therapeutic approaches is limited to symptomatic relief.•Graphene nanomaterials (GNs) prevent protein aggregation and upregulate autophagic events.•GN-protein interactions are reviewed in context of preventing neurodegeneration.
Regulatory T cells (Tregs) play an essential role in maintaining immune tolerance and suppressing inflammation. However, Tregs present major hurdle in eliciting potent anti-cancer immune responses. ...Therefore, curbing the activity of Tregs represents a novel and efficient way towards successful immunotherapy of cancer. Moreover, there is an emerging interest in harnessing Treg-based strategies for augmenting anti-cancer immunity in different types of the disease. This review summarises the crucial mechanisms of Tregs’ mediated suppression of anti-cancer immunity and strategies to suppress or to alter such Tregs to improve the immune response against tumors. Highlighting important clinical studies, the review also describes current Treg-based therapeutic interventions in cancer, and discusses Treg-suppression by molecular targeting, which may emerge as an effective cancer immunotherapy and as an alternative to detrimental chemotherapeutic agents.
•Tregs are crucial in maintaining immune tolerance and suppressing inflammation.•Tregs present a major obstacle to eliciting potent anti-tumor immune responses.•The review summarizes current Treg-based therapeutic interventions in cancer.•Treg can be an effective cancer immunotherapy target.
Anti-cancer immunity; Cancer, CD8+ T cells; CD4+ T cells; Regulatory T cells; Tumor-infiltrating lymphocytes.
Calcium channel blockers (CCBs) are a heterogeneous group of drugs often used in the therapy for hypertension and angina. Though CCBs are generally similar in terms of their efficacy yet, they differ ...in their ability of causing selective inhibition in the contractility of vascular smooth muscle in comparison to cardiac muscle. Felodipine is one of the most vascular selective of the available CCBs and it has no negative inotropic effects at clinically administered doses. Focus of this review is to comprehensively summarize the pharmacokinetics, efficacy, safety and tolerability of felodipine. This review is based on evaluation of relevant literature on felodipine using meta-database PubMed and ScienceDirect and internet search engine (Google Scholar). Clinical studies summarized in this review testify, on technical lines, the clinical efficacy, safety and placebo- like tolerability profile of felodipine, administered alone as well as in combination.
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