Herein, we aim to evaluate the photodetector performance of various nanostructured materials (thin films, 2-D nanolayers, 1-D nanowires, and 0-D quantum dots) in ultraviolet (UV), visible, and ...infrared (IR) regions. Specifically, semiconductor-based metal oxides such as ZnO, Ga2O3, SnO2, TiO2, and WO3 are the majority preferred materials for UV photodetection due to their broad band gap, stability, and relatively simple fabrication processes. Whereas, the graphene-based hetero- and nano-structured composites are considered as prominent visible light active photodetectors. Interestingly, graphene exhibits broad band spectral absorption and ultra-high mobility, which derives graphene as a suitable candidate for visible detector. Further, due to the very low absorption rate of graphene (2%), various materials have been integrated with graphene (rGO-CZS, PQD-rGO, N-SLG, and GO doped PbI2). In the case of IR photodetectors, quantum dot IR detectors prevails significant advantage over the quantum well IR detectors due to the 0-D quantum confinement and ability to absorb the light with any polarization. In such a way, we discussed the most recent developments on IR detectors using InAs and PbS quantum dot nanostructures. Overall, this review gives clear view on the development of suitable device architecture under prominent nanostructures to tune the photodetector performance from UV to IR spectral regions for wide-band photodetectors.
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•Systematically classified the photodetector materials based upon their spectral absorbance.•Basic mechanism and prominent figures of merit of photodetectors are explained.•The dependence of PD performance on various nanostructures are discussed.•Most recent advancements in photodetectors are addressed by expound of their problems.
•Flaxseed oil yield, colour and chemical properties were influenced by MW roasting.•MW roasting had improved TPC, antioxidant activity and oxidative stability of oil.•HMF was detected in flaxseed oil ...roasted at 540 W for 10 min.•MW roasting at 540 W for 10 min is recommended for flaxseed oil extraction.
In this study, flaxseeds roasted at microwave (MW) powers of 180, 360 and 540 W for 5 and 10 min were evaluated for their influence on oil yield, chemical properties, carotenoid and chlorophyll contents, total phenolic content (TPC), radical scavenging activity (RSA), oxidative stability index (OSI), fatty acid composition and Maillard reaction products (MRPs). MW roasting at 540 W for 10 min significantly increased the oil yield, TPC, OSI, RSA, a* value, browning index, carotenoid and chlorophyll contents while decreased the L* and b* values of flaxseed oil (FSO). MRPs were detected only in oil of flaxseeds roasted at 540 W for 10 min. The level of stearic, palmitic, oleic, linoleic and α-linolenic acids were slightly changed and FTIR spectra showed minor variation in peak intensities of oils from different MW roasted flaxseeds. MW roasting (540 W for 10 min) is recommended for improving quality and stability characteristics of FSO.
In this review, we have comprehensively elaborated on the various materials suitable for the infrared (IR) bolometer applications and also provided the underlying mechanisms of various reported ...device structures. IR bolometers are used for thermal imaging, operates by changing the resistance of the sensing layer upon absorbing the IR radiation from the source and which in turn modifies into the electric output signals. We first look at the most fundamental developments associated with the materials and device architecture for advancements in the uncooled microbolometers. Starting from traditional materials like α-Si and VOx, and novel materials like carbon nanotubes (CNTs) and few metal oxides, we have given special attention to enhancement in the temperature coefficient of resistance (TCR) of the bolometric materials for improving the device performance. Specifically, most of the uncooled microbolometer technology is dominated by the conventional materials, like VOx and amorphous (α)-Si in terms of performance and large-scale production. The α-Si based microbolometers are able to achieve the TCR values about − 3%/K at room temperature. However, the boron (B) doping and hydrogenated-Si (Si:H(B)) enhances the TCR value (−4.5%/K). The framework of VOx film with gold-black IR absorber provide the TCR about − 2.4%/K along with high responsivity (8.4 ×104 V/W). Recent advancements in the development of metal oxide (TiO2−x) based thin films enable very high TCR values (−2.56%/K) along with lower 1/f noise parameter (3.16 ×10-12). These findings can be understood in terms of much sensitive oxygen vacancies to control the device performance. In addition, TCR values can be further tuned along with the reduction of noise through the interfacial interaction with CNTs and other doping elements. Therefore, non-stoichiometric TiO2−x thin films serves as potential candidate to replace the traditional α-Si and VOx based uncooled microbolometers.
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•Systematically classified the microbolometer materials based upon their performance.•Basic mechanism and prominent figures of merit of microbolometers are explained.•The dependence of TCR performance on various bolometric materials are discussed.•Most recent advancements in uncooled bolometers are addressed by expound of their problems.
The present study was designed to investigate the sperm damages occurring in acrosome, plasma membrane, mitochondrial activity, and DNA of fresh, equilibrated and frozen–thawed buffalo semen by ...fluorescent probes. The stability of sperm acrosome and plasma membrane stability, mitochondrial activity and DNA status were assessed by fluorescein conjugated lectin
Pisum sativum
agglutinin, Annexin–V/propidium iodide, JC-1 and TUNEL assay, respectively, under the fluorescent microscope. The damages percentage of acrosome integrity was significantly increased during equilibration and freezing–thawing process. The stability of sperm plasma membrane is dependent on stability of phosphatidylserine (PS) on the inner leaflet of plasma membrane. The frozen–thawed sperm showed externalization of PS leading to significant increase in apoptotic, early necrotic and necrotic changes and lowered high mitochondrial membrane potential as compared with the fresh sperm but all these parameters were not affected during equilibration. However, the DNA integrity was not affected during equilibration and freezing–thawing procedure. In conclusion, the present study revealed that plasma membrane and mitochondria of buffalo sperm are more susceptible to damage during cryopreservation. Furthermore, the use of fluorescent probes to evaluate integrity of plasma and acrosome membranes, as well as mitochondrial membrane potential and DNA status increased the accuracy of semen analyses.
•DA and IR roasting showed impact on BCS oil yield and chemical properties.•Roasting favored pigment transfer and changed the color of BCS oil.•DA roasting was more effective than IR roasting in ...improving oil quality.•HMF, BI, and OSI were increased by DA roasting at high temperature.•Recommended DA roasting condition is 180 °C for 10 min.
Black cumin seed (BCS) is a novel oil source with potential health benefits. This study investigates the influence of infrared (IR) and dry air (DA) roasting (140, 160 and 180 °C for 5 and 10 min) on BCS oil quality characteristics. Results revealed that the oxidative stability index (OSI), Maillard reaction products (MRPs), chlorophyll and carotenoid contents were increased while acid value (AV), peroxide value (PV) and color values were decreased in DA roasted (180°C for 10 min) BCS oil compared to other DA and IR treatments. DA and IR roasting slightly influenced the fatty acid composition (FAC) of BCS oils. FTIR spectra showed minor changes in peak intensities (at 2854, 2929 and 3008 cm−1) of DA and IR roasted BCS oils. DA roasting proved more effective than IR roasting. The oil from the DA roasted BCS at 180°C for 10 min had significantly higher oil quality and oxidative stability.
Solid state reaction synthesis was employed for the production of triclinic zinc molybdate (α-ZnMoO4) crystal. X-ray diffraction (XRD) pattern, Rietveld refinement analysis, Fourier-transform ...infrared (FT-IR) and Fourier-transform Raman (FT-Raman) spectroscopy confirmed that α-ZnMoO4 exhibit a triclinic structure without evidence of any impurity phase. FT-IR spectroscopy gives information about vibrational features of Mo–O in the MoO4 clusters. The 13 active vibrational modes were observed in Raman spectra from 100 to 1000 cm−1. UV–Vis absorption spectroscopy was used for calculation of optical band gap. The band gap (Eg) of 4.12 eV was observed for a direct allowed transition. The photoluminescence (PL) spectrum of α-ZnMoO4 gives intense green emission. Microwave dielectric constant (εr), temperature coefficient at the resonant frequency (τf) and Q x f value were measured by Hakki-Coleman method and found to be 8.05, −121.81 ppm/oC and 48320 GHz respectively. These results suggested the applications of ZnMoO4 in LEDs, scintillating detectors and microwave device.
•Synthesis of triclinic α-ZnMoO4 by using a solid state reaction method.•Confirmation of single phase (triclinic) formation using Rietveld refinement, XRD data, FT-IR and Raman spectra.•Investigation of optical properties using UV–Vis and photoluminescence spectroscopy.•Investigation of microwave dielectric property using Hakki-Coleman technique.
SARS-CoV-2 was reported to induce cell fusions to form multinuclear syncytia that might facilitate viral replication, dissemination, immune evasion, and inflammatory responses. In this study, we have ...reported the types of cells involved in syncytia formation at different stages of COVID-19 disease through electron microscopy.
Bronchoalveolar fluids from the mild (n = 8, SpO2 > 95%, no hypoxia, within 2-8 days of infection), moderate (n = 8, SpO2 90% to ≤ 93% on room air, respiratory rate ≥ 24/min, breathlessness, within 9-16 days of infection), and severe (n = 8, SpO2 < 90%, respiratory rate > 30/min, external oxygen support, after 17th days of infection) COVID-19 patients were examined by PAP (cell type identification), immunofluorescence (for the level of viral infection), scanning (SEM), and transmission (TEM) electron microscopy to identify the syncytia.
Immunofluorescence studies (S protein-specific antibodies) from each syncytium indicate a very high infection level. We could not find any syncytial cells in mildly infected patients. However, identical (neutrophils or type 2 pneumocytes) and heterotypic (neutrophils-monocytes) plasma membrane initial fusion (indicating initiation of fusion) was observed under TEM in moderately infected patients. Fully matured large-size (20-100 μm) syncytial cells were found in severe acute respiratory distress syndrome (ARDS-like) patients of neutrophils, monocytes, and macrophage origin under SEM.
This ultrastructural study on the syncytial cells from COVID-19 patients sheds light on the disease's stages and types of cells involved in the syncytia formations. Syncytia formation was first induced in type II pneumocytes by homotypic fusion and later with haematopoetic cells (monocyte and neutrophils) by heterotypic fusion in the moderate stage (9-16 days) of the disease. Matured syncytia were reported in the late phase of the disease and formed large giant cells of 20 to 100 μm.
The influence of oxygen partial pressure (pO2) on the ultra-violet (UV) photodetector performance of WO3 thin films was studied. Here, the thickness of the WO3 thin films decreased from 225 nm to ...150 nm with increasing the pO2 from 5% to 20%. The crystallinity of WO3 films decreased at higher pO2. The XPS analysis confirmed that the WO3 film deposited at 10% of pO2 had the more oxygen vacancies. The grain size of WO3 films decreased at higher pO2 grown conditions owing to the fragmentation of the oxide formation through the plasma. From current-voltage (I–V) measurements of WO3/Ti device, the ohmic-contact implies the formation of the metal-semiconductor junction with very less barrier height (φB) and it helps to the trapping of generated electrons for potential photodetector. Due to the higher number of incoming photons, the photocurrent was found to be increased as the power density increases. Finally, the WO3 film deposited at 10% of pO2 exhibits the higher photocurrent and quick rising time and hence this optimized thin film is suitable for UV-A photodetector.
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•We describe an enhanced WO3 photodetector performance at 10% of pO2.•Possible mechanism of charge carrier generation and electron trapping was projected.•The higher charge carrier generation was achieved at 10% of pO2 samples.•Lower barrier height aids to the trapping of generated electrons for potential photodetector.•Superior photodetector characteristics were achieved comparing with other metal oxides.
•The novel and functional components from SBR, SBA and SBI are extracted.•Higher Ara/Xyl values of extracts from SBR indicates its highly branched structure.•TDF and IDF contents in original sorghum ...were in the following order: SBA˃SBI˃SBR.•Both the drum and spray dried CRF from all sorghum sources show high WHC.•Hemi. B from all three sorghum sources had an excellent emulsion stability.
This study was undertaken to isolate and characterize three carbohydrate-rich fractions: Hemicellulose A (Hemi. A), Hemicellulose B (Hemi. B) and cellulose-rich residue (CRF) from sorghum bran (SBR), sorghum bagasse (SBA) and sorghum biomass (SBI). The monosaccharide composition of the Hemi. A and Hemi. B fractions was determined, indicating that SBR has a highly branched structure. The analysis of insoluble dietary fiber (IDF), soluble dietary fiber (SDF) and total dietary fiber (TDF) showed that TDF and IDF contents in original sorghum materials were in the following order: SBA˃SBI˃SBR. CRF from SBA was rich in IDF. Hemi. B fractions were completely soluble in water and so they were rich in SDF. CRFs from all sorghum sources show high water holding capacity (22.76 to 35.27g water/g CRF). The emulsion stability study showed that the Hemi. B from all sorghum sources had a better emulsion stability than the well-studied corn fiber gum (CFG).
•Soya lecithin-based extender, liposome-based extender and egg yolk-based extender were compared.•Sperm kinetics and motility was found higher in liposome-based extender among these ...extenders.•Liposome-based extender performed better in vitro assessment of sperm longevity test.•Sperm cryopreserved in liposome-based extender travelled significantly more distance in cervical mucus.
Demand for alternative of egg yolk in freezing extenders have increased in recent years due to variability in egg yolk composition, risk of microbial contamination and presence of steroid hormones. The alternative to egg yolk-based extender (EY) can be soya lecithin-based extender (SL) and liposome-based extender (LP). However, the efficacy of SL is still a matter of debate. Few studies have been performed on the effect of LP but to date evaluation of buffalo semen cryopreserved in LP has not been studied. Therefore, this study was designed to compare SL and LP with conventional EY for evaluation of post-thaw quality of buffalo semen. Results showed that total, progressive and rapid sperm motility were found significantly higher (P<0.05) in LP among these extenders. In vitro assessment of post-thaw sperm longevity has also resulted in better maintenance of sperm kinetics and motility in LP in comparison to other extenders. Furthermore, sperm cryopreserved in LP travelled significantly more (P<0.05) distance in cervical mucus as compared to SL and EY. Therefore, it can be concluded that the LP is more efficient than SL and EY for the cryopreservation of buffalo semen.
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