Abstract In the fast-evolving realm of communication technology, microstrip patch antennas (MPAs) are in high demand owing to their compact size, lightweight, inexpensive, ease of integration, and ...compatibility with modern electronic devices. This research focuses on the synthesis of ZnAl 2 O 4 Ca (ZAC) ceramic nanoparticles using an economical sol–gel method suitable for microstrip patch antenna applications. The structural analysis study of ZAC nanoparticles confirmed the polycrystalline nature with 8.1 nm of crystallite size whereas an investigation of functional groups showed the corresponding vibration modes. Morphological investigation revealed the spherical grains having their mean diameter of 12.32 nm. The dielectric property’s examination, revealed the dielectric permittivity of 13, loss tangent of 0.02, and conductivity of 67 μΩ −1 cm −1 . Furthermore, a prototype patch antenna fabricated using ZAC ceramics demonstrated a dual-band performance at frequencies 2.8 GHz and 4.8 GHz, with return losses of − 25.78 dB and − 28.5 dB, respectively. This work suggests the suitability of ZAC ceramic nanoparticles for use in WLAN applications.
Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare, multi-system, inflammatory disease, belonging to the group of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides ...(AAV). Previously known as Churg-Strauss syndrome, EGPA is characterised by late-onset asthma, eosinophilia and vasculitis affecting small-to-medium vessels. This disease behaves differently in many aspects to the other AAV and is often excluded from AAV studies. The disease is poorly understood and, due to it rarity and unique manifestations, there has been limited research progress to optimise our understanding of its complex pathogenesis and ability to develop management options – although the success of interleukin-5 inhibitors such as Mepolizumab has been a welcome development. The pathophysiology also appears to be different to other forms of AAV and hence management strategies that work for AAV may not fully apply to this condition. There is no current standard therapy for EGPA although corticosteroids are almost universally used for treatment alongside other agents and encouraging modes of treatment continue to evolve beyond glucocorticoid immunosuppression (including interleukin-5 inhibition). There is therefore a significant ongoing unmet need for efficacious steroid-sparing immunosuppressing agents. The prognosis also diverges from other forms of AAV, and we discuss the pathophysiology, clinical features and diagnosis, management and prognosis in this article.
•EGPA. an important part of the ANCA-associated vasculitides (AAV) has significant differences in pathophysiology, treatments and outcomes compared to other forms of AAV.•This can display either eosinophilic-predominant or vasculitic-predominant features and has low rates of ANCA positivity.•Targeting IL-5 offers a promising mode of treatment for refractory and relapsing disease.
When seedlings of rice (Oryza sativa L.) cultivar Pant-12 were raised in sand cultures containing 80 and 160 μM Al³⁺ in the medium for 5-20 days, a regular increase in Al³⁺ uptake with a concomitant ...decrease in the length of roots as well as shoots was observed. Al³⁺ treatment of 160 μM resulted in increased generation of superoxide anion (O₂ -) and hydrogen peroxide (H₂O₂), elevated amount of malondialdehyde, soluble protein and oxidized glutathione and decline in the concentrations of thiols (-SH) and ascorbic acid. Among antioxidative enzymes, activities of superoxide dismutase (SOD EC 1.15.1.1), guaiacol peroxidase (Guaiacol POX EC 1.11.1.7), ascorbate peroxidase (APX EC 1.11.1.11), monodehydroascorbate reductase (MDHAR EC 1.6.5.4), dehydroascorbate reductase (EC 1.8.5.1) and glutathione reductase (EC 1.6.4.2) increased significantly, whereas the activities of catalase (EC EC 1.11.1.6) and chloroplastic APX declined in 160 μM Al³⁺ stressed seedlings as compared to control seedlings. The results suggest that Al³⁺ toxicity is associated with induction of oxidative stress in rice plants and among antioxidative enzymes SOD, Guaiacol POX and cytosolic APX appear to serve as important components of an antioxidative defense mechanism under Al³⁺ toxicity. PAGE analysis confirmed the increased activity as well as appearance of new isoenzymes of APX in Al³⁺ stressed seedlings. Immunoblot analysis revealed that changes in the activities of APX are due to changes in the amounts of enzyme protein. Similar findings were obtained when the experiments were repeated using another popular rice cv. Malviya-36.
Fusarium wilt of lentil caused by
Fusarium oxysporum
f. sp.
lentis
(
Fol
) is a destructive pathogen limiting lentil production in India. In the present study,
Secreted in Xylem
(
SIX
) effectors ...genes were explored in Indian races of
Fol
and also a diagnostic tool for reliable detection of the disease was developed. Four
SIX
effectors genes,
SIX11, SIX13, SIX6
and
SIX2
were identified in 12 isolates of
Fol
belonging to seven races.
SIX11
was present in all the races while
SIX 13
was absent in race 6 and
SIX6
was present only in race 4. The phylogenetic analysis revealed the conserved nature of the
SIX
genes within the
forma specialis
and showed sequence homology with
F. oxysporum
f. sp.
pisi
. The presence of three effectors,
SIX11
,
SIX13
and
SIX6
in race 4 correlates with high disease incidence in lentil germplasms. The
in-silico
characterization revealed the presence of signal peptide and localization of the effectors. Further
SIX11
effector gene present in all the isolates was used to develop
Fol
-specific molecular marker for accurate detection. The marker developed could differentiate
F. oxysporum
f. sp.
lycopersici
,
F. solani
,
F. oxysporum
,
Rhizoctonia solani
and
Sclerotium rolfsii
and had a detection limit of 0.01ng μL
− 1
. The effector-based marker detection helps in the unambiguous detection of the pathogen under field conditions.
Two low cost adsorbents were prepared by using groundnut husk and were tested for the removal of chromium. All the experiments were carried out in batch process with chromium spiked samples of ...drinking water. Silver impregnated groundnut husk carbon and groundnut husk carbon were tested for the removal of chromium(VI). Effects of adsorbent quantity, pH, contact time and agitation rate were investigated on removal of chromium. The adsorption data were fitted well by Freundlich adsorption isotherm. Approximately, 97% of hexavalent chromium was removed at pH 3 within 5
h. It was found that adsorbents chemically modified with an oxidizing agent demonstrated better chromium removal capabilities as compared to pure adsorbents in terms of their adsorption rate. On the basis of present studies, it can be concluded that groundnut husk carbon oxidized with silver treatment, has a higher chromium adsorption capacities.
Mycobacterium tuberculosis (Mtb) becomes dormant and phenotypically drug resistant when it encounters multiple stresses within the host. Inability of currently available drugs to kill latent Mtb is a ...major impediment to curing and possibly eradicating tuberculosis (TB). Most in vitro dormancy models, using single stress factors, fail to generate a truly dormant Mtb population. An in vitro model that generates truly dormant Mtb cells is needed to elucidate the metabolic requirements that allow Mtb to successfully go through dormancy, identify new drug targets, and to screen drug candidates to discover novel drugs that can kill dormant pathogen.
We developed a novel in vitro multiple-stress dormancy model for Mtb by applying combined stresses of low oxygen (5%), high CO(2) (10%), low nutrient (10% Dubos medium) and acidic pH (5.0), conditions Mtb is thought to encounter in the host. Under this condition, Mtb stopped replicating, lost acid-fastness, accumulated triacylglycerol (TG) and wax ester (WE), and concomitantly acquired phenotypic antibiotic-resistance. Putative neutral lipid biosynthetic genes were up-regulated. These genes may serve as potential targets for new antilatency drugs. The triacylglycerol synthase1 (tgs1) deletion mutant, with impaired ability to accumulate TG, exhibited a lesser degree of antibiotic tolerance and complementation restored antibiotic tolerance. Transcriptome analysis with microarray revealed the achievement of dormant state showing repression of energy generation, transcription and translation machineries and induction of stress-responsive genes. We adapted this model for drug screening using the Alamar Blue dye to quantify the antibiotic tolerant dormant cells.
The new in vitro multiple stress dormancy model efficiently generates Mtb cells meeting all criteria of dormancy, and this method is adaptable to high-throughput screening for drugs that can kill dormant Mtb. A critical link between storage-lipid accumulation and development of phenotypic drug-resistance in Mtb was established. Storage lipid biosynthetic genes may be appropriate targets for novel drugs that can kill latent Mtb.
Interactive effects of two heavy metal pollutants Cd and Pb in the growth medium were examined on their uptake, production of reactive oxygen species (ROS), induction of oxidative stress and ...antioxidative defence responses in Indica rice (Oryza sativa L.) seedlings. When rice seedlings in sand culture were exposed to 150 μM Cd (NO₃)₂ or 600 μM Pb (CH₃COO)₂ individually or in combination for 8–16 days, a significant reduction in root/shoot length, fresh weight, relative water content, photosynthetic pigments and increased production of ROS (O₂˙⁻ and H₂O₂) was observed. Both Cd and Pb were readily taken up by rice roots and localisation of absorbed metals was greater in roots than in shoots. When present together in the growth medium, uptake of both the metals Cd and Pb declined by 25–40 %. Scanning electron microscope (SEM) imaging of leaf stomata revealed that Pb caused more distortion in the shape of guard cells than Cd. Dithizone staining of roots showed localisation of absorbed Cd on root hairs and epidermal cells. Both Cd and Pb caused increased lipid peroxidation, protein carbonylation, decline in protein thiol and increase in non-protein thiol. The level of reduced forms of non-enzymic antioxidants glutathione (GSH) and ascorbate (AsA) and their redox ratios (GSH/AsA) declined, whereas the activities of antioxidative enzymes superoxide dismutase (SOD) and guaiacol peroxidase (GPX) increased in metal treated seedlings compared to controls. In-gel activity staining also revealed increased intensities of SOD and GPX isoforms with metal treatments. Catalase (CAT) activity increased during early days (8 days) of metal exposure and declined by 16 days. Results suggest that oxidative stress is an important component in expression of Cd and Pb toxicities in rice, though uptake of both metals gets reduced considerably when present together in the medium.
The present investigation evaluated the ability of an antioxidative defense system in terms of the tolerance against salinity-induced oxidative stress and also explored a possible relationship ...between the status of the components of an antioxidative defense system and the salt tolerance in Indica rice (Oryza sativa L.) genotypes. When the seedlings of a salt-sensitive cultivar was grown in sand cultures containing different NaCl concentrations (7 and 14 dS m⁻¹) for 5–20 days, a substantial increase was observed in the rate of superoxide anion (O ₂ ·⁻ ) production, elevated levels of H₂O₂ and thiobarbituric acid reactive substances (TBARS) which indicated an enhancement in lipid peroxidation. A declination in the level of thiol clearly indicated an increase in the protein oxidation as well as a decline in the reduced forms of ascorbate (AsA) and glutathione (GSH) and the ratios of their reduced to oxidized forms occurred in the salt-sensitive seedlings. Similar treatment caused a very little alteration or no change in the levels of these components in the seedlings of salt-tolerant cultivar. The activity of antioxidative enzymes superoxide dismutase (SOD), its isoform Cu/Zn-SOD and ascorbate peroxidase (APX) increased in both the cultivars against salinity. In salt-sensitive seedlings, the activity of the various enzymes, guaiacol peroxidase (GPX), catalase (CAT), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and glutathione reductase (GR) increased at moderate salinity treatment of 7 dS m⁻¹ NaCl while the activities of these enzymes declined with higher salinity level of 14 dS m⁻¹ NaCl. However, a consistent increase was observed in the activities of these enzymes of salt-tolerant seedlings with an increase in the duration and the level of the salinity treatment. The results suggest that a higher status of antioxidants (AsA and GSH) and a coordinated higher activity of the enzymes (SOD, CAT, GPX, APX, and GR) can serve as the major determinants in the model for depicting salt tolerance in Indica rice seedlings.
Ab-initio calculations based on density functional theory (DFT) have been performed to study the optical properties of pure graphene and have been compared to that of individual boron (B), nitrogen ...(N) and BN co-doped graphene sheet. The effect of doping has been investigated by varying the concentrations of dopants from 3.125% (one atom of the dopant in 32 host atoms) to 18.75% (six dopant atoms in 50 host atoms) for individual B and N doping and from 6.25% (one B/N pair in 32 host atoms) to 75% for BN co-doping. Positions of the dopants have also been varied for the same concentration of substitution doping. The dielectric matrix has been calculated within the random phase approximation (RPA) using VASP (Vienna ab-initio Simulation Package) code. The dielectric function, absorption spectrum and energy loss-function of single layer graphene sheet have been calculated for light polarization parallel and perpendicular to the plane of graphene sheet and compared with doping graphene. The calculated dielectric functions and energy-loss spectra are in reasonable agreement with the available theoretical and experimental results for pure graphene. It has been found that individual B and N doping does not significantly affect the imaginary dielectric function and hence the absorption spectra. However, significant red-shift in absorption towards the visible range of the radiation at high doping is found to occur for the B/N co-doping. The results can be used to tailor the optical properties of graphene in the visible region.
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•This paper reports DFT results on optical properties of doped graphene.•Calculations have been made for parallel and perpendicular light polarizations.•The individual B and N doping does not significantly affect the imaginary dielectric function.•However high co-doping result in significant red-shift of absorption in visible region.
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