Gd3+-substituted BiFeO3 perovskite nanoparticles: facile synthesis, characterization, and applications in heterogeneous catalysis

We present the combustion-based synthesis of BiFeO₃ (BFO) and Gd:BiFeO₃ perovskite nanoparticles. XRD analysis demonstrates that the undoped BFO (x = 0) perovskite sample shows a single perovskite phase with a rhombohedral structure. However, increase in the Gd³⁺ content from x = 0.05 and 0.15 to 0.25 led to the occurrence of a structural phase transformation from rhombohedral (BiFeO₃) to orthorhombic (Bi₂Fe₄O₉). With an increase in the Gd-dopant the average crystallite size of rhombohedral structures increased from 16 to 23 nm. The perovskite samples were examined using XPS, which confirmed the presence of Bi³⁺, Gd³⁺, Fe²⁺, and O²⁺ ions. FT-IR spectroscopy indicated the existence of elemental functional groups in the synthesized perovskite nanoparticles. Furthermore, the direct band gap measured by DRS reduced from 2.16 to 2.0 eV as the Gd concentration increased. The nanoparticles of the BFO perovskite had an uneven shape, a tendency to agglomerate, and fused grains with defined grain boundaries. At ambient temperature, both the undoped and Gd:BFO perovskite nanoparticles exhibit a ferromagnetic characteristic. It was found that the BET surface area of the undoped and Gd-doped BFO perovskite nanoparticles varied progressively from 4.38 to 33.52 m² g^-1. The catalytic oxidation studies conducted in a batch reactor under air conditions revealed that the synthesized catalysts, in particular, Gd:BFO (x = 0.25), exhibited higher conversion and selectivity efficiencies for glycerol (con. 100% and sel. 99.5%, respectively).

Factors Associated with Prehospital Delay in Patients with Acute Stroke in South India

Background

Early hospital presentation is critical in the management of acute ischemic stroke. The effectiveness of stroke treatment is highly dependent on the amount of time lapsed between onset of symptoms and treatment. This study was aimed to identify the factors associated with prehospital delay in patients with acute stroke.

Material and Methods

A cross-sectional descriptive study was conducted in Sri Ramachandra University Hospital, India. A total of 210 patients hospitalized in the stroke unit were included. Patients' data were obtained by interviewing the patient and/or accompanying family member and by reviewing their medical records using a standard questionnaire. Associations were determined between prehospital delay (≥4.5 h) and variables of interest by using univariate and multivariate logistic regression analyses.

Results

The prehospital delay was observed in 154 patients (73.3%) and the median prehospital delay was 11.30 h. The following are the factors significantly (P < 0.05) attributed for the delay in presenting to the hospital: contextual factors like using public transport (bus), taxi, time of onset of symptoms, 7 pm-3 am; family history of stroke, perceived cognitive and behavioral factors like, wishing or praying for the symptoms to subside on its own, hesitation to travel due to long distance, delay in arranging transport, and arranging money for admission and wasting time by shopping for general practitioners, nursing homes, and hospitals. The presence of stroke symptom, headache, significantly decreased the prehospital delay.

Conclusions

Prehospital delay is high in South India and influenced by clinical, contextual, and cognitive/behavioral factors.

AN EMPIRICAL STUDY OF CANCER CLASSIFICATION TECHNIQUES BASED ON THE NEURAL NETWORKS

Cancer is one of the most common dreadful diseases prevailing worldwide, and patients with cancer are rescued only when the cancer is detected at a very early stage. Early detection of cancer is appropriate as in the fourth stage, but the chance of survival is limited. The symptoms of cancers are rigorous, and therefore, all the symptoms should be studied properly before the diagnosis. Thus, an automatic prediction system is necessary for classifying the tumor, i.e. malignant or benign tumor. Over the past few years, cancer classification is increased rapidly, but there is no general technique to find novel cancer classes (class discovery) or to assign tumors to known classes. Accordingly, this survey analyzes distinct cancer classification techniques. Thus, this review article provides a detailed review of 50 research papers presenting the suggested cancer classification techniques, like Deep learning-based techniques, Neural network-based techniques, and Hybrid techniques. Moreover, an elaborative analysis and discussion are made based on the year of publication, utilized datasets, accuracy range, evaluation metrics, implementation tool, and adopted classification methods. Eventually, the research gaps and issues of various cancer classification schemes are presented for extending the researchers towards a better future scope.

Synthesis, Structural, Optical and Dielectric Properties of Nanostructured 0-3 PZT/PVDF Composite Films

Nanostructured PbZr0.52Ti0.48O3 (PZT) powder was synthesized at 500 °C-800 °C using sol-gel route. X-ray diffraction and Rietveld analysis confirmed the formation of perovskite structure. The sample heat treated at 800 °C alone showed the formation of morphotropic phase boundary with coexistence of tetragonal and rhombohedral phase. The PZT powder and PVDF were used in 0-3 connectivity to form the PZT/PVDF composite film using solvent casting method. The composite films containing 10%, 50%, 70% and 80% volume fraction of PZT in PVDF were fabricated. The XRD spectra validated that the PZT structure remains unaltered in the composites and was not affected by the presence of PVDF. The scanning electron microscopy images show good degree of dispersion of PZT in PVDF matrix and the formation of pores at higher PZT loading. The quantitative analysis of elements and their composition were confirmed from energy dispersive X-ray analysis. The optical band gap of the PVDF film is 3.3 eV and the band gap decreased with increase in volume fraction of PZT fillers. The FTIR spectra showed the bands corresponding to different phases of PVDF (α, β, γ) and perovskite phase of PZT. The thermogravimetric analysis showed that PZT/PVDF composite films showed better thermal stability than the pure PVDF film and hydrophobicity. The dielectric constant was measured at frequency ranging from 1 Hz to 6 MHz and for temperature ranging from room temperature to 150 °C. The composite with 50% PZT filler loading shows the maximum dielectric constant at the studied frequency and temperature range with flexibility.

Antibacterial Activity of Rhizome of Curcuma aromatica and Partial Purification of Active Compounds

The hexane extract of Curcuma aromatica, a plant belonging to the family Zingiberaceae was tested on 10 bacterial strains (clinical isolates and standard strains). Agar diffusion method was adopted for determining the antibacterial activity of the extract. The hexane extract was found to be active against all Gram-positive strains tested, but inactive against Gram-negative strains. The minimum inhibitory concentration and minimum bactericidal concentration were determined and found to be 539 μg/ml. The phytochemical analysis of hexane extract by gas chromatography mass spectrometry revealed the presence of 13 compounds. The crude hexane extract was partially purified by thin layer chromatography. The zone showing good antibacterial activity was analysed further by gas chromatography mass spectrometry, UV/Vis spectrophotometry and Fourier transform infrared spectroscopy, which indicated the probable presence of germacrone.

Assessment of the attitude of staff nurses towards hospitalised psychiatric patients in Kolar (Karnataka)

As in other fields, the awareness of patients regarding their rights in seeking right or opting for particular modality of treatment is on the increase. This study sought to assess the attitude of staff nurses towards psychiatric patients hospitalised in a hospital in Karnataka. The study included 15 Diploma and as many Degree level nursing students. Using convenience sampling technique, authors conclude that graduate nurses were more articulate in asserting that hospitalised psychiatric patients were justified in seeking information about their illness and treatment or declining treatment than diploma students. The authors also suggest in-service education programme for nurses so as to inculcate a more positive attitude towards mentally ill patients.

QSAR Analysis of Indazole Estrogens as Selective β-Estrogen Receptor Ligands: Rationalization of Physicochemical Properties

Quantification of structure activity relationships was performed on a series of indazole estrogen analogs, for their relative beta estrogenic receptor agonist activity, in order to understand the essential structural requirements for selectivity of indazole estrogen analogs for beta-estrogenic receptor over alpha-estrogenic receptor. The de novo and Hansch approach suggested that the 3(rd) position of indazole nucleus (R(1)) is decisive for the selectivity of molecules towards beta-estrogenic receptor over alpha-estrogenic receptor. The study also depicted that the substitution of polar group at R(1) position might prove helpful in the beta-estrogenic receptor selectivity (ER(beta/alpha )).

Rationalization of physicochemical characters of 1,5-diarylpyrazole analogs as dual (COX-2/LOX-5) inhibitors: A QSAR approach

Arachidonic acid metabolizing enzymes cyclooxygenases and lipoxygenases lead to the formation of various eicosanoids involved in variety of human diseases, like inflammation, fever, pain, rheumatic and osteoarthritis, etc. Non-steroidal anti-inflammatory drugs are useful tools in the treatment of prostaglandin mediated complications. The development of dual inhibitors may prevent a drift of arachidonic acid metabolism towards the other pathway, leading to potential side effects. Hence emphasis was focused on quantification of structure-activity relationship, with a view to delineating the influence of key COX-2/LOX-5 activity, to explore structural insights to aid the designing of safer dual inhibitors. The quantification of the structural features of 1,5-diarylpyrazole analogs with various biological activities gave some important structural insights, i.e. Hy (hydrophilic factor) and Mor17v (3D molecular representation of structure based on electron diffraction code). These two physicochemical properties may be helpful in development of more selective dual COX-2/LOX-5 inhibitors.

Performance evaluation of common effluent treatment plant for tanneries at Pallavaram CETP

The Pallavaram Tanners Industrial Effluent Treatment Company Limited has been a forerunner in ensuring cleaner and safe environment. The project was implemented by a company formed by the tanners of the Pallavaram area. Tamil Nadu Pollution Control Board (TNPCB) was the counterpart of UNIDO and took the overall responsibility for implementation of the project. The present study has been undertaken to evaluate performance efficiency of the treatment plant. Water samples were collected at different stages of treatment units and analysed for the major water quality parameters, such as pH, biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS) and total dissolved solids (TDS). The performance efficiency of each unit in treating the pollutants was calculated. The generated data presented evidence to that the common effluent treatment plant has been working with the norms of TNPCB and meeting the discharge standard limits.