o-Thioquinones undergo facile hetero Diels–Alder reactions with cyclic dienes leading to novel heterocyclic compounds.
o-Thioquinones undergo facile hetero Diels–Alder reactions with cyclic dienes ...leading to novel heterocyclic compounds.
o-Benzoquinones undergo facile hetero Diels-Alder reaction with tetracyclone leading to cyclopentab1,4benzodioxinones.
Hetero Diels-Alder reactions of different substituted
o-benzoquinones with ...tetracyclone are described.
To help unlicensed users to use the maximum available licensed bandwidth, an opportunistic communication technology called cognitive radio, (CR) is developed. It has recently attracted a great deal ...of research interest. Even though the majority of future wireless devices will be mobile, mobility is yet unexplored in the context of CR. There is no proper framework for mobile CRs to effectively use the available licensed bandwidth. In this paper, a spectrum sensing and accessing framework considering user mobility is proposed. This work removes all the presumptions about user mobility, established in the previous CR based literature. The smooth random mobility model is considered for creating a realistic mobile environment. The CRs are free to travel and cooperate to sense and use the licensed channels. A cognitive base station coordinates all the CRs. The nodes are grouped into clusters based on their geographical placement and all the nodes in a cluster are further split up into small groups based on their relative mobility. Transform Domain Communication System, (TDCS) is employed by the CRs to access the spectrum. The sensing technique being used by each CR is the double threshold energy detection method. Under this framework, the whole licensed channels can be exploited in each cluster if there are enough number of CRs in that cluster. A Matlab simulation is provided for examining the efficiency of the proposed framework.
Silver nanoparticles have been synthesized using green and chemical methods.
Mussaenda frondosa
(
M. frondosa
) leaf extract and sodium citrate used as reducing and stabilizing agents for the ...synthesis of silver nanoparticles (AgNPs) in green and chemical methods. The synthesized nanoparticles were characterized using UV-vis spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermal gravimetric analysis (TGA), and transmission electron microscopy (TEM). The antioxidant activity of green and chemically synthesized nanoparticles was evaluated by DPPH (1, 1-Diphenyl-2-picrylhydrazyl) assay and observed that green synthesized nanoparticles possess remarkable antioxidant activity compared to chemically synthesized nanoparticles and it can be used for enormous applications in the biomedical field. The present study enlightens the importance of green synthesized AgNPs using
M. frondosa
leaf extract over the chemically synthesized one.
Introduction: Mycotic keratitis is a major cause of monocular blindness in tropical and subtropical climates. The difficulty to differentiate mycotic keratitis (fungal keratitis) from other causes, ...limited availability of antifungal agents, their poor ocular penetration and indolent course of the disease lead to significant ocular complications and vision loss. Aim: To analyse the typical presenting clinical characteristics which predict the final visual outcome in microbiologically proven mycotic keratitis over two years in a tertiary eye care centre of South Kerala, India. Materials and Methods: The present study was a retrospective study, conducted on 165 eyes of 165 patients treated for culture proven mycotic keratitis in the Regional Institute of Ophthalmology, South Kerala, India, from August 2018 to July 2020. Best Corrected Visual Acuity (BCVA), detailed history including history of injury and systemic diseases were noted. Treatment outcome was measured as BCVA at the end of three months. The association between age, sex, presenting features like size, depth, margins and colour of the keratitis and the final BCVA were assessed by linear regression analysis. Results: Among 165 eyes, 90 (54.6%) had a history of injury in the affected eye. The majority of the keratitis had a size of 2-6 mm in 150 (90.9%), peripheral in location in 107 (64.8%) and involvement up to anterior 2/3rd of the stroma in 93 (56.4%). Of 165, 112 (67.9%) of the ulcers had a greyish white or pigmented colour, 118 (71.5%) had dry texture and 115 (69.7%) had feathery margins. Raised exudates were present in 99 (60%) patients, satellite lesions in 29 (17.6%), immune ring in 6 (3.6%), endothelial plaque in 20 (12.1%) and hypopyon in 40 (24.2%) at the time of diagnosis. The important predictors of final BCVA at three months were the larger size of the ulcer, increase in depth, central location, presence of hypopyon and poor vision at presentation. Conclusion: Small superficial keratitis with good vision at presentation had a better final BCVA. Dry texture and feathery edges were seen more frequently in fungal keratitis. Large, deep, central keratitis and poor vision at presentation are associated with worse final visual outcome after treatment.
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•The synthesis of highly fluorescent CDs using Alternanthera sessilis leaves as the precursor is reported for the first time.•The fabricated CDs act as highly sensitive and selective ...sensors for the fluorescent and electrochemical detection of Cu2+ and Zn2+ ions respectively..•The detection limits of the suggested sensors were of nanomolar range.•The synthesized CDs exhibited high anticancer and antimicrobial potentials.
Herein, the green synthesis of novel fluorescent carbon dots (CDs) from the Alternanthera sessilis plant by a simple, eco-friendly, and facile hydrothermal method was reported. The developed CDs exhibit green fluorescence and have a size of 5.25 nm. Various analyses reveal outstanding features, including high quantum yield, good photostability, and excellent hydrophilicity of the as-synthesized CDs. It was used as a dual-mode probe for the sensing of Cu2+ ions and Zn2+ ions in an aqueous system. Efficient sensing of Cu2+ ions takes place by static quenching of fluorescence with a detection limit of 28.03 nM. CDs-coated glassy carbon electrode was used to perform the electrochemical detection of Zn2+ ions in an aqueous system with high selectivity and sensitivity, and the LOD value was found to be 2.28 nM. The LC50 value of the fabricated CDs against the human breast cancer cell line is 89.85 µL/mL. Also, the antimicrobial efficacy of the CDs was examined against Escherichia coli, Staphylococcus Aureus, and Aspergillus niger, and the results indicate the high toxicity of the CDs against all tested microbial strains.
Background
Hepatic mesenchymal hamartoma (HMH) is the second most common benign hepatic tumor in the pediatric age group. The etiology of HMH is unclear. Theories include abnormal hepatic mesenchyme, ...a reactive change or a proliferative lesion. The condition can present prenatally in USG as a mass, high output cardiac failure, pulmonary hypertension, respiratory distress, and abdominal distension or mass in older children. We present this case to discuss an extremely rare presentation of a comparatively rare disease and to emphasise the need for a high index of suspicion even if the patient presents with symptoms common for that age.
Case presentation
A 7-day-old male baby with an uneventful antenatal period, born by vaginal delivery, with a birth weight of 3.1 kg and normal APGAR scores, presented with jaundice, poor feeding, and labored breathing noticed on the same day itself. Examination revealed a grossly distended abdomen with a mass of size 8 × 7 cm occupying the right side down to the right iliac fossa, crossing midline and dullness continuous with liver dullness. On investigation an abnormal liver function test with unconjugated hyperbilirubinemia was seen. USG and CECT abdomen were suggestive of HMH with close proximity to hepatic vessels. Exploratory laparotomy and near total excision with marsupialisation was done. Histopathology report was suggestive of HMH. A 2-year follow-up was normal.
Conclusion
This case of HMH presented as neonatal jaundice with unconjugated hyperbilirubinemia which is a rarity. We had to limit our surgery to near total excision and marsupialisation due to its proximity to vascular structures.
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