Structural and magnetic properties of nanocrystalline BaFe12O19 synthesized by microwave-hydrothermal method

Nanocrystalline BaFe12O19 powders were prepared by microwave-hydrothermal method at 200 °C/45 min. The as-synthesized powders were characterized by using X-ray diffraction (XRD), thermogravimetry (TG) and differential thermal analysis (DTA). The present powders were densified at different temperatures, i.e., 750, 850, 900 and 950 °C for 1 h using microwave sintering method. The phase formation and morphology studies were carried out using XRD and field emission scanning electron microscopy (FE-SEM). The average grain sizes of the sintered samples were found to be in the range of 185–490 nm. The magnetic properties such as saturation magnetization and coercive field of sintered samples were calculated based on magnetization curves. A possible relation between the magnetic hysteresis curves and the microstructure of the sintered samples was investigated

Evaluation of Lateral Condylar Guidance by Clinical and Radiographic Methods – Hanau’s Formula Revisited: An Invivo Study

INTRODUCTION: Success of complex prosthodontic procedures is not only enhanced by accurate simulation of the horizontal condylar path but also by simulating lateral condylar path of patient on an articulator. If condylar guidances are not recorded accurately, it will lead to occlusal interferences during mandibular movements. This may also increase chairside denture adjustment time, which can be frustrating for both the patient and the prosthodontist. AIM AND OBJECTIVES: The purpose of this study is to use radiographic technique to determine the lateral condylar guidance and compare these values with those obtained using Hanau’s formula, and to evaluate whether there are differences between the right and left paths of the condyles. JUSTIFICATION FOR THE STUDY: Various clinical methods for recording the condylar guidance are intraoral check bite method, graphic tracings, and functional recordings. Accuracy of graphic tracings is affected by patient-related factors such as neuromuscular control of the individual, stability of record bases as well as stability of recording media. The accuracy and reliability of the methods used for programming the semi-adjustable articulators determine the accuracy in occlusion. The current recommended average settings using the Hanau’s formula, commonly used by clinicians is questionable, and thus reassessment is needed. MATERIALS AND METHODS: Centre: Department of Prosthodontics and Crown & Bridge, Vivekanandha Dental College for Women, Tiruchengode. No. of samples: Completely edentulous patients (n=20). OUTCOME MEASURES: A statistically significant difference between the methods to determine Bennett angle is a good indicator to ascertain Bennett angle radiographically and minimizing the errors in complete dentures caused by the articulator calibration and an arbitrary formula calculation for L. The lateral interocclusal records obtained in this study can further be used in the Hanau™ Wide-Vue articulator to check and correct the occlusal errors thereby obtaining a balanced complete denture. METHOD: Articulator was modified with sectioned protractor for obtaining per degree interval calibration. After the impression procedures and procurement of master casts, the occlusal rims were constructed. The occlusal rims were inserted into the patient’s mouth and the vertical dimension at occlusion was recorded. Facebow transfer was done and gothic arch tracing was performed to obtain centric, protrusive, and lateral records. With the protrusive records, the horizontal condylar guidance [H] was adjusted and the Bennett’s angle [L] was calculated using the formula. With the tracing device in mouth, cranial radiographs in SMV projection was obtained. Each radiograph was traced and superimposed for Bennett angle determination. The Bennett angle obtained from both formula and radiographic tracings were tabulated and subjected to statistical analysis. STATISTICAL ANALYSIS: The data was subjected to statistical analysis by Mann-whitney-U test to find the correlation between the lateral condylar guidance between left and right sides and between the two methods on each side. Mann-whitney-U test was applied to check the difference between the right and left side condylar guidance determined by the two methods. RESULT: A statistically significant difference exists between LCG-C using Hanau’s formula and LCG-M using SMV projection method. Thus, the data supports rejection of the null hypothesis. LCG-M values exhibited no variation on both sides and there is no significant difference. Thus, the data supports rejection of the null hypothesis for this variable also. CONCLUSION: Within the limitations of the study, the following conclusions were deduced: 1.). There is no significant difference between the right and left LCG-C and LCG-M. 2.). There exist a huge difference between the LCG calculated from the conventional Hanau’s formula and LCG measured from the SMV projection radiographs

Effect of brimonidine on central corneal thickness in normal tension glaucoma patients

Background: Brimonidine is a potent ocular hypotensive agent widely used in glaucoma treatment. A reduction in central corneal thickness can lead to an underestimation of intraocular pressure by Goldmann applanation tonometry and vice versa. The aim of this study is to determine whether brimonidine has an effect on central corneal thickness.Methods: 30 eyes of patients who attended the Ophthalmology OPD between the time period October 2017 and June 2018 who were newly diagnosed with normal tension glaucoma with no history of any systemic illness or not on any medication were included. Each patient underwent a complete ophthalmic evaluation including fundus examination, visual field assessment, intraocular pressure, central corneal thickness measurement by pachymetry before as well as 1 month and 6 months after starting treatment with 0.2% topical brimonidine twice daily.Results: Administration of brimonidine 0.2% resulted in an increase in central corneal thickness from 525±21 µm before starting brimonidine to 528±21 µm (p<0.05) after 1 month and 535±20 µm (p<0.001) after 6 months. It also resulted in a reduction in intraocular pressure from an initial value of 16±2 mmHg before starting brimonidine to 14±2 mmHg (p<0.05) and 13±2 mmHg (p<0.05), 1month and 6 months after starting treatment, respectively.Conclusions: The data presented in this study show that topical administration of 0.2% brimonidine twice daily results in a significant increase in central corneal thickness in patients with normal tension glaucoma

Structural and Magnetic Properties of Manganese Zinc Ferrite Nanoparticles Prepared by Solution Combustion Method Using Mixture of Fuels

The structural analysis and magnetic investigation Mn1−xZnxFe2O4 with stoichiometry (x=0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.0) were synthesized by solution combustion method using mixture of fuel this is first of its kind. As synthesized Mn–Zn nanoferrites were characterized by X-ray Diffractometer (XRD), Transmission electron microscopy (TEM) at room temperature. The magnetic domain relaxation was investigated by inductance spectroscopy (IS) and the observed magnetic domain relaxation frequency (fr) was increased with the increase in grain size. The Room temperature magnetic properties were studied using vibrating sample magnetometer (VSM). It was observed that the real and imaginary part of permeability (µ' and µ?), saturation magnetization (Ms), remanance magnetization (Mr) and magneton number (Mr/Ms) were decreases gradually with increasing Zn2+ concentration. The decrease in the saturation magnetization may be explained as, the Zn2+ concentration increases the relative number of ferric ions on the A sites diminishes and this reduces the A–B interaction. Hence synthesized materials are good for high frequency applications

Effect of Sm3+-Gd3+ co-doping on dielectric properties of Mn-Zn ferrites synthesized via combustion route

Nanocrystalline Mn0.4 Zn0.6SmxGdyFe2-(x+y)O4 where x and y = 0.01,0.02,0.03,0.04 and 0.05 were synthesized by Solution combustion method. The as prepared samples were characterized by X-ray diffractometer (XRD), Transmission electron microscopy (TEM) and Vibrating sample Magnetometer (VSM) at room temperature. From the XRD the crystallite size were found increases with the increase of Sm3+-Gd3+ ions concentration while lattice parameter found to decreases. The real and imaginary part of permittivity (ε′ and ε′′) were undertaken in the wide frequency range 1GHz to 5GHz at room temperature. It is found that the real and imaginary part of permittivity’s are increasing with increasing Sm3+ and Gd3+ concentration. The magnetic behaviour of as synthesized nano ferrites reveals that, the saturation magnetization (MS), remanence magnetization (MR) is increasing with increasing Sm and Gd concentration. The g-value, peak-to-peak linewidth and spin concentration evaluated from EPR spectra correlated with cations occupancy. These electromagnetic properties clearly indicates that the synthesized materials are the good candidates for L and C band frequency

iEEG based Epileptic Seizure Detection using Reconstruction Independent Component Analysis and Long Short Term Memory Network

In recent decades, an epileptic seizure is a neurological disorder, which is commonly detected from intracranial Electroencephalogram (iEEG) signals. However, the visual interpretation and inspection of iEEG signal is subjective variability, a time-consuming mechanism, slow and vulnerable to errors. In this research article, an automated epileptic seizure detection model is proposed to highlight the above-mentioned concerns. The proposed automated model integrates the Reconstruction Independent Component Analysis (RICA) and Long Short Term Memory (LSTM) for seizure detection. In the proposed model, RICA is utilized to extract the features from the normalized iEEG signals, and then the obtained feature vectors are fed to the LSTM network for classification, which effectively classifies inter-ictal and ictal iEEG signals. This experimental outcome showed that the proposed RICA-LSTM model achieved an accuracy of 98.92%, sensitivity of 99.01%, specificity of 98.68%, balanced accuracy of 99.24%, and f-score of 98.25% in epileptic seizure recognition on the SWEC-ETHZ iEEG database, which is better compared to the conventional machine learning classifiers

Effect of Sm3+-Gd3+ on structural, electrical and magnetic properties of Mn-Zn ferrites synthesized via combustion route

Nanocrystalline Mn0.4 Zn0.6 SmxGdyFe2-(x+y)O4 (x = y = 0.01, 0.02, 0.03, 0.04 and 0.05) were synthesized by combustion route. The detailed structural studies were carried out through X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM). The results confirms the formation of mixed spine phase with cubic structure due to the distortion created with co-dopants substitution at Fe site in Mn-Zn ferrite lattice. Further, the crystallite size increases with an increase of Sm3+-Gd3+ ions concentration while lattice parameter and lattice strain decreases. Furthermore, the effect of Sm-Gd co-doping in Mn-Zn ferrite on the room temperature electrical (dielectric studies) studies were carried out in the wide frequency range 1 GHz-5 GHz. The magnetic studies were carried out using vibrating sample magnetometer (VSM) under applied magnetic field of 1.5T and also room temperature electron paramagnetic resonance (EPR) spectra's were recorded. From the results of dielectric studies, it shows that the real and imaginary part of permittivities are increasing with variation of Gd3+ and Sm3+ concentration. The magnetic studies reveal the decrease of remnant, saturation magnetization and coercivity with increasing of Sm3+-Gd3+ ion concentration. The g-value, peak-to-peak line width and spin concentration evaluated from EPR spectra correlated with cations occupancy. The electromagnetic properties clearly indicate that these materials are the good candidates which are useful at L and C band frequency. © 2015 Elsevier B.V

Efficacy of cabergoline in the prevention of severe ovarian hyperstimulation syndrome in high-risk women undergoing assisted reproductive technology treatment

Background: Ovarian hyperstimulation syndrome (OHSS) is a severe and potentially life-threatening complication of controlled ovarian stimulation (COH). Cabergoline has been tried as a preventive measure for OHSS in high-risk women undergoing assisted reproductive technology (ART) treatment. Our study was done to assess the effectiveness of cabergoline in preventing severe OHSS in high-risk women undergoing ART treatment.Methods: This is a prospective interventional study done among patients undergoing ART with serum estradiol levels >4000 pg/ml on the day of hCG administration were included in the study. Women undergoing ART with serum estradiol levels >4000 pg/ml on the day of hCG administration, were assigned into two groups using random number allocation. Women in treatment group received cabergoline 0.5 mg daily for 8 days from the day of hCG administration and control group did not receive Cabergoline therapy. The patients in both groups were followed up to study the incidence and severity of OHSS in that treatment cycleResults: The incidence of severe OHSS was two in each group with clinical and ultrasound evidence of ascites. Embryo transfer was cancelled in one patient in each group in view of severe OHSS with tense ascites. One patient in treatment group had severe OHSS that needed peritoneal fluid tapping with fresh frozen plasma administration. Life threatening complications were not encountered in any of the patients with high risk for OHSS included in the study.Conclusions: Cabergoline did not prevent the incidence of severe OHSS in patients at high risk for OHSS in our study. Large randomized trials would be needed to confirm the findings of our study

Awareness and post counselling acceptance of eye donation in a tertiary care centre in Northern Kerala

Background: Corneal diseases are among the major cause of vision loss and blindness in the world today. Corneal transplantation remains the mainstay of treatment. Hence creation of awareness carries paramount importance. Aim of this study is to assess the awareness about eye donation amongst attendants of deceased patients, their willingness to donate eyes and the reasons for poor donation rate. To assess the efficacy of grief counselling by Eye Donation Counsellor (EDC), its impact on the conversion rateMethods: A prospective hospital based study was done in 135 participants (guardians of deceased subjects) admitted in intensive care units, from June 2017 to June 2018. Counsellor accompanied with a junior resident would first screen the cases. Relatives of suitable cases were approached and counselled in a systematic manner following a standard interview pattern. Responses were noted in a predesigned proforma.Results: Among 618 deceased cases 135 potential donors were identified.57.8% next of kin were aware of the concept of eye donation, but 42.2% were not. After counselling, willingness for eye donation was seen in 54.1%, others refused. Among 57.8% kin who were aware, 51.3% gave consent. Prior knowledge of eye donation, literacy and socioeconomic status did not have any significant influence on willingness. Counselling was found to be the best method to facilitate eye donation.Conclusions: An active counselling by eye donation counsellor is the main factor which is responsible for eye donation