Abstract
A series of Eu
3+
ions doped Ca
0.05
Y
1.93-
xO
3
:0.02Ho
3+
(CYO:Ho
3+
,xEu
3+
) nanophosphors having multicolour tuneability have been synthesised by following a simplistic solution ...combustion approach. The synthesised samples have been characterised by employing X-ray diffraction (XRD), Transmission electron microscope (TEM), and Fourier transforms infrared spectroscopy (FTIR). The optical properties have been engrossed by UV–visible and photoluminescent excitation and emission spectra, and decay lifetimes measurements. The characteristic emission, which occurs due to the f-f transition of Ho
3+
and Eu
3+
has been observed in emission spectra with excitation of 448 nm. By adjusting the doping ratio of Ho
3+
/Eu
3+
, the as-synthesized nanophosphor accomplishes multicolour tunability from green-yellow to red. Emission spectra and decay lifetime curve recommend dipole–dipole interaction causes energy transfer from Ho
3+
→ Eu
3+
. The energy transfer process from Ho
3+
to Eu
3+
has been confirmed through electric dipole–dipole interaction with critical distance 15.146 Å. Moreover, temperature dependent emission spectra show the high thermal stability with an activation energy ⁓ 0.21 eV, with the quantum efficiency of 83.6%. CIE coordinate illustrates that the singly doped Ho
3+
and Eu
3+
lie in the green and red region, respectively, while the as-synthesized CYO:Ho
3+
,xEu
3+
shows tunability from green to red with low CCT and high colour purity values. Hence, the CYO:Ho
3+
,xEu
3+
nanophosphor may be a near-UV excited multicolour colour-tunable pertinent candidate with potential prospects for multicolour- display and near-ultraviolet lighting applications.
Herein, we demonstrate the fabrication of highly capacitive activated carbon (AC) using a bio-waste Kusha grass (
Desmostachya bipinnata
), by employing a chemical process followed by activation ...through KOH. The as-synthesized few-layered activated carbon has been confirmed through X-ray powder diffraction, transmission electron microscopy, and Raman spectroscopy techniques. The chemical environment of the as-prepared sample has been accessed through FTIR and UV–visible spectroscopy. The surface area and porosity of the as-synthesized material have been accessed through the Brunauer–Emmett–Teller method. All the electrochemical measurements have been performed through cyclic voltammetry and galvanometric charging/discharging (GCD) method, but primarily, we focus on GCD due to the accuracy of the technique. Moreover, the as-synthesized AC material shows a maximum specific capacitance as 218 F g
−1
in the potential window ranging from − 0.35 to + 0.45 V. Also, the AC exhibits an excellent energy density of ~ 19.3 Wh kg
−1
and power density of ~ 277.92 W kg
−1
, respectively, in the same operating potential window. It has also shown very good capacitance retention capability even after 5000th cycles. The fabricated supercapacitor shows a good energy density and power density, respectively, and good retention in capacitance at remarkably higher charging/discharging rates with excellent cycling stability. Henceforth, bio-waste Kusha grass-derived activated carbon (DP-AC) shows good promise and can be applied in supercapacitor applications due to its outstanding electrochemical properties. Herein, we envision that our results illustrate a simple and innovative approach to synthesize a bio-waste Kusha grass-derived activated carbon (DP-AC) as an emerging supercapacitor electrode material and widen its practical application in electrochemical energy storage fields.
In the year since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and with understanding of the etiology of the coronavirus disease 2019 (COVID-19) pandemic, it has ...become clear that most infected individuals achieve some form of immunity against the virus with relatively few reported reinfections. A number of vaccines have already achieved emergency use authorization based on data from large phase 3 field efficacy clinical trials. However, our knowledge about the extent and durability of this immunity, and the breadth of vaccine coverage against SARS-CoV-2 variants is still evolving. In this narrative review, we summarize the latest and rapidly developing understanding of immunity to SARS-CoV-2 infection, including what we have learned about the key antigens of SARS-CoV-2 (i.e., the spike protein and its receptor-binding domain), their importance in vaccine development, the immediate immune response to SARS-CoV-2, breadth of coverage of emerging SARS-CoV-2 variants, contributions of preexisting immunity to related coronaviruses, and duration of immunity. We also discuss lessons from newer approaches, such as systems serology, that provide insights into molecular and cellular immune responses elicited and how they relate to the trajectory of infection, and potentially inform immune correlates of protection. We also briefly examine the limited research literature on immune responses in special populations, such as pregnant women and children.
Purpose
This study aims to analyze the state of knowledge on the relationship between leadership and the firm’s supply chain. The study identifies and examines the existing literature, unveils ...research gaps and suggests future research directions.
Design/methodology/approach
Adopting a systematic review process, a total of 110 articles published in top-ranked academic journals (A* and A category as per ABDC-2019 list) were analyzed. Descriptive, cluster, thematic and regression analyses of citations were performed to garner insights.
Findings
The review outcome shows an upward trend of articles studying the influence of leadership in the supply chain. With the highest number of articles, developed countries and manufacturing companies have been the research contexts of the research studies. Clustering reveals eight significant areas where the leader’s involvement in the supply chain is discussed, with several sub-themes emerging within each cluster. Finally, the regression analysis of citations shows that only the journal’s quality matters the most in receiving the highest citation for the articles.
Research limitations/implications
As this study considered only A* and A-ranked journals of the ABDC-2019 list, there is a risk of excluding some relevant articles.
Originality/value
While the current literature deliberates on recent trends in the supply chain, such as the application of Industry 4.0 practices, this review revolves around the classical theme of leadership and demonstrates its importance in the supply chain. The study is among the first to conduct a bibliometric analysis of articles deliberating on leadership and supply chain issues by grouping the articles into clusters and themes. In the end, the clusters and themes were conceptualized into the “House of Supply Chain Leadership,” of which leadership forms the foundation.
Anti-viral triterpenes: a review Darshani, Priya; Sen Sarma, Shreya; Srivastava, Amit K. ...
Phytochemistry reviews,
12/2022, Letnik:
21, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Triterpenes are naturally occurring derivatives biosynthesized following the isoprene rule of Ruzicka. The triterpenes have been reported to possess a wide range of therapeutic applications including ...anti-viral properties. In this review, the recent studies (2010–2020) concerning the anti-viral activities of triterpenes have been summarized. The structure activity relationship studies have been described as well as brief biosynthesis of these triterpenes is discussed.
Extracellular vesicles (EVs) are membrane-surrounded structures released by most cell types. They are characterized by a specific set of proteins, lipids and nucleic acids. EVs have been recognized ...as potent vehicles of intercellular communication to transmit biological signals between cells. In addition, pathophysiological roles of EVs in conditions like cancer, infectious diseases and neurodegenerative disorders are well established. In recent years focus has been shifted on therapeutic use of stem cell derived-EVs. Use of stem cell derived-EVs present distinct advantage over the whole stem cells as EVs do not replicate and after intravenous administration, they are less likely to trap inside the lungs. From the therapeutic perspective, the most promising cellular sources of EVs are mesenchymal stem cells (MSCs), which are easy to obtain and maintain. Therapeutic activity of MSCs has been shown in numerous animal models and the beneficial paracrine effect of MSCs may be mediated by EVs. The various components of MSC derived-EVs such as proteins, lipids, and RNA might play a specific therapeutic role. In this review, we characterize the role of EVs in immune and central nervous system (CNS); present evidences for defective signaling of these vesicles in neurodegeneration and therapeutic role of EVs in CNS.
Hydroxyproline is a non-essential amino acid found in collagen and few other extracellular animal proteins. It's two isomeric forms trans-4-hydroxy-L-proline and trans-3-hydroxy-L-proline play a ...crucial role in collagen synthesis and thermodynamic stability of the triple-helical conformation of collagen and associated tissues. Various abnormalities in hydroxyproline metabolism have been shown to play key roles in the pathophysiology and pathogenesis of different diseases. The elevated level of hydroxyproline is observed in several disorders, e.g., graft versus host disease, keloids, and vitiligo while its decreased level is a marker of poor wound-healing. This review explores the potential of using hydroxyproline as a biochemical marker to understand the pathogenesis, molecular pathophysiology and treatment of these diseases. The review concludes with an outlook on the scope and challenges in the clinical implementation of hydroxyproline as a biomarker.
Remote sensing can be used to map tillage practices at large spatial and temporal scales. However, detecting such management practices in smallholder systems is challenging given that the size of ...fields is smaller than historical readily-available satellite imagery. In this study we used newer, higher-resolution satellite data from Sentinel-1, Sentinel-2, and Planet to map tillage practices in the Eastern Indo-Gangetic Plains in India. We specifically tested the classification performance of single sensor and multiple sensor random forest models, and the impact of spatial, temporal, or spectral resolution on classification accuracy. We found that when considering a single sensor, the model that used Planet imagery (3 m) had the highest classification accuracy (86.55%) while the model that used Sentinel-1 data (10 m) had the lowest classification accuracy (62.28%). When considering sensor combinations, the model that used data from all three sensors achieved the highest classification accuracy (87.71%), though this model was not statistically different from the Planet only model when considering 95% confidence intervals from bootstrap analyses. We also found that high levels of accuracy could be achieved by only using imagery from the sowing period. Considering the impact of spatial, temporal, and spectral resolution on classification accuracy, we found that improved spatial resolution from Planet contributed the most to improved classification accuracy. Overall, it is possible to use readily-available, high spatial resolution satellite data to map tillage practices of smallholder farms, even in heterogeneous systems with small field sizes.
The recent outbreak of the novel coronavirus, SARS‐CoV‐2, has emerged to be highly pathogenic in nature. Although lungs are considered as the primary infected organs by SARS‐CoV‐2, some of the other ...organs, including the brain, have also been found to be affected. Here, we have discussed how SARS‐CoV‐2 might infect the brain. The infection of the respiratory center in the brainstem could be hypothesized to be responsible for the respiratory failure in many COVID‐19 patients. The virus might gain entry through the olfactory bulb and invade various parts of the brain, including the brainstem. Alternatively, the entry might also occur from peripheral circulation into the central nervous system by compromising the blood–brain barrier. Finally, yet another possible entry route could be its dispersal from the lungs into the vagus nerve via the pulmonary stretch receptors, eventually reaching the brainstem. Therefore, screening neurological symptoms in COVID‐19 patients, especially toward the breakdown of the respiratory center in the brainstem, might help us better understand this disease.
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