Study of Crystal Structure and Electrical Properties on Lead Titanate and Lead Zirconate Titanate Based Ceramic Oxides

The lead based perovskite material (PT, PZT) has so many technological applications such as:multilayer capacitor, dielectric resonator, thin film resistor, piezoelectric transducers, elecrostrictive actuators, hydrogen sensor, electro optical modulator, laser host, switch magnetic bubble memory etc. The property of the lead based material can also be enhanced by substituting different transition materials within the perovskite.Again there is a very less report on the detailed crystal structure study (Employing the Rietveld Method) of the modified lead based perovskite ceramics.There were no detailed study on crystal structure and physical properties of Pb1-xLaxTiO3 (PLT) at high concentration of La content.The introduction of an optimized amount of lanthanum (La) not only increases the stability but also softens the ferroelectric properties of the material.Also there was not much report on the detailed crystal structure (Employing the Rietveld method) and physical properties of B site modification of PLT with general formula (Pb0.70La0.30)(Ti1-xAx)O3,(A = Mn and Al). The main objective to study this material was to explore the structural and electrical properties of both iso(Mn3+) and aliovant (Al3+) substitution on the B site of Pb0.7La0.3TiO3 cubic perovskite. Manganese (Mn3+) as an acceptor ion may replace Ti4+ site and the addition segregates at grain boundaries. Mn doping in lead titanate is also a good candidate for fabricating piezoelectric devices. Mn belongs to valence unstable ions; it can affect the stability of the material.Aluminium does not have a bonding d-orbit or d-electrons, and has a stable valence and solely displays a valence of 3+,different from the isovalent substitutions for Ti4+.So the aliovalent substitutions of Al3+ for Ti4+ in Pb0.7La0.3TiO3 would be interesting for studying the doping effect on the crystal structure, lattice dynamics and electrical properties.The oxygen ion vacancy concentration in rare earth (La3+) and manganese modified lead titanate could have an important contribution to the electrical response of these materials. There are lots of reports on the structural and electrical properties of modified lead zirconate titanate ceramics in the MPB region. But there is hardly found few reports on the detailed crystalvii structure (Employing the Rietveld method) of lead zirconate titanate in and around the MPB region which overcomes the existence of two phases.The doping substituent can either occupy A-site, Bsite or both as donor or acceptor based on chemical valance with respect to the original ions.The substitution of the transition elements of the B-site will modify the electrical properties of the ferroelectric materials.It is also well known that the fluctuation of the oxidation state of the transition metal ions (Fe3+, Mn3+) results in the formation of oxygen ion vacancies to reserve the local electrical neutrality and causes thermally activated conduction

Radiological significance of high-resolution computed tomography for elderly pulmonary tuberculosis patients : an analysis with culture test

Purpose: Pulmonary tuberculosis (PTB) is one of the major health problems in the elderly population, causing significant morbidity and mortality. The aim of this study is to evaluate the significance of the high-resolution computed tomography (HRCT) modality for the diagnosis of PTB, in comparison to culture test. Material and methods: Thoracic HRCT images of the study population, comprising 124 patients clinically suspected for PTB with smear and culture reports, were analysed for sensitivity and specificity of the HRCT test. Features of active PTB were centrilobular nodules, 'tree-in-bud' pattern densities, macro-nodules, consolidations, cavitary lesions, ground-glass opacities, and miliary nodules. Results: Among the study population, 108 cases presented HRCT features of active PTB and the remaining cases were negative but had presented a few features mimicking PTB. As inferred from positive culture test results, 106 cases had active PTB, the remaining cases were culture negative for PTB. False-positive (FP) or 'type I error' cases, and false-negative (FN) or 'type II error' cases were ascertained by Bayes' theorem. Sensitivity (true positive rate) and specificity (true negative rate) of HRCT test were 0.8125 and 0.8571, respectively. Conclusions: For proper diagnosis the predictive capability, as two values of 'a posteriori probability', was computed; the mean value of 'a posteriori probability' for HRCT was 0.6358. When its culture test was positive, the HRCT test was 69.56-92.85% efficient in ascertaining positive results with a sample; on the other hand, when its culture test was negative it was 66.66-100% efficient for a negative result. Thus, the HRCT test is considerably dependable

A CORRELATIVE STUDY ON SPINDLE CELL SARCOMA WITH CYTO-HISTOLOGICAL GRADING BY CONVENTIONAL METHODS IN AN INDIAN TERTIARY CARE TEACHING HOSPITAL

Objective: Spindle cell sarcomas constitute an important component of soft tissue sarcomas, where accurate grading is more important than histologic subtypes to plan treatment strategies and determine prognosis. To assess whether histologic criteria for grading sarcomas could be applied to fine needle aspiration biopsy (FNAB) specimens of adult spindle cell sarcomas without knowledge of sarcoma subtypes. Furthermore, correlate this grading with histologic Federation Nationale Des Centres de lutte contre le cancer (FNCLCC) grading system and find out the percentage of accuracy of FNAB grading. Methods: Hundred cases were studied by fine needle aspiration cytology (FNAC), among them 50 cases found to be spindle cell sarcoma; in only 42 cases surgical specimens were available. Each aspiration being spread into two or more slides. Subsequently, biopsy was done and studied. Technique used - grading of FNAB specimens and corresponding surgical specimens. Result: Grading of FNAB specimens done taking into account four parameters - nuclear atypia, nuclear variation (nuclear contour, chromatin, nucleoli, and nuclear overlap), mitotic figure, and necrosis. Grading of surgical specimens done by FNCLCC system. The overall results were correlated for both FNAC and biopsy concordance and statistically analyzed. From there the sensitivity and specificity were calculated as 95.23% and 80.76%, respectively. Conclusion: Histologic criteria for grading sarcomas in adults could be applied to FNAC specimens of spindle cell sarcomas with 88% accuracy. While comparing the diagnosis given by FNAC and biopsy, it revealed the true positive were 40 cases, true negative 42 cases, false positive 10 cases, and false negative (FN) 2 cases.Â

COMPUTED TOMOGRAPHIC EVALUATION OF INFERIOR TURBINATE HYPERTROPHY IN ADULT INDO-DRAVIDIAN PATIENTS WITH DEVIATED NASAL SEPTUM

Objective: Aim of the study was to evaluate the prevalence and significance of inferior turbinate hypertrophy (ITH) in adult indo-dravidian patients with deviated nasal septum (DNS). Methods: Analysis of sinonasal computerized tomography (CT) images of 86 patients having DNS was done during October 2015-December 2016 for evaluation of severity of the associated ITH. Values of maximum width of medial mucosa, bone and total width of the turbinate were measured. Patients with inflammatory or expansile sinonasal masses were excluded. Results: Total 86 patients with varying degrees of septal deviation with ages ranging from 18 to 72 years (mean age of 42.8 years) were distributed as: Group I, mild cases and Group II, moderate and severe DNS cases. Patients having ITH on the contralateral side of deviation were included in the study group. The dimensions of the ITH were evaluated. The medial mucosal component of the ITH underwent maximum hypertrophy as compared to bone and lateral mucosa components. The average medial mucosa, bone and total turbinate widths of the inferior nasal concha as well as lateral offset in Group II DNS cases were 5.21 mm, 1.76 mm, 9.96 mm and 8.74 mm, respectively. Total width and width of medial mucosa of ITH in relation to the severity of septal deviation was statistically significant (p=0.0001 and 0.0098). Conclusion: Present study evaluated the relationship between DNS and compensatory ITH. The findings support the decision to excise the inferior turbinate at the time of septoplasty, because of the significant mucosal expansion

Radiological significance of isolated ethmoid sinus infections in asymptomatic patients of recurrent acute rhinosinusitis

Background: Recurrent acute rhinosinusitis (RARS) being a low form chronic rhinosinusitis (CRS), is relatively under diagnosed many times because of lack of awareness regarding pattern of the disease presentation. Aim of the study is to evaluate the radiological significance of isolated ethmoid sinusitis in patients of RARS during the asymptomatic interval in between acute episodes of rhinosinusitis.Methods: Total 124 patients with history suggestive of RARS who had undergone computed tomography study of brain during April 2015 to October 2016 for indications other than sinonasal diseases, were evaluated for isolated ethmoid sinusitis in the department of Radiology. Patients having any inflammatory or expansile sinonasal masses were excluded.Results: Of total 124 patients of RARS aged from 18 to 70 years (mean age of 38.6 years), the study population included only seventy-two (58%) patients having isolated ethmoid sinus infections, were classified in to mild unilateral group I (46%) cases with grade I or II sinus infections and relatively severe bilateral group II (54%) cases having grade III or IV infections. Infective process involving two to three ethmoid cells each on either side is the most common variety encountered in 39% cases. Prevalence of infective process was fairly equal among all age groups. Statistical correlation between the severity of RARS in patients having group II variety of isolated ethmoid sinus infections was found highly significant.Conclusions: Isolated ethmoid sinus infections are commonly encountered CT findings in adult RARS patients while they are asymptomatic from acute episodes of rhinosinusitis

Radiological significance of the sinonasal anatomical variants in recurrent acute rhinosinusitis patients

Background: Recurrent acute rhinosinusitis (RARS), a low form chronic rhinosinusitis is frequently under evaluated. The significance of sinonasal anatomical variants of osteomeatal complex (OMC) and spheno-ethmoidal (SE) recess regions in patients of RARS is assessed.Methods: Retrospective analysis of coronal sinonasal computed tomography images of 120 RARS patients presented with sinonasal anatomical variants during November 2013 to October 2016 was carried out. Patients with acute and expansile sinonasal lesions are excluded.Results: Sinonasal anatomical variants in the regions of OMC and SE recess are responsible for obstruction of normal mucociliary drainage of corresponding paranasal sinuses in presence of inflammation predisposing to RARS. Anatomical variants of nasal septum were, deviated nasal septum (DNS) in 86 (72%) and septal spur in 58 (48%) patients. Anatomical variants in OMC region were, pneumatized middle turbinate (concha bullosa) in 50 (48%), paradoxical middle turbinate in 38 (28%), giant ethmoid bulla in 35 (32%), agger nasi cell in 29 (38%), Haller cell in 23 (15%), pneumatised uncinate process in 20 (18%), medialized uncinate process in 18 (22%) and septated maxillary sinus in 5 (4%) patients. Anatomical variants in SE recess were superior concha bullosa in 14 (12%) and septal bullosa in 11 (9%) patients.Conclusions: OMC pattern of recurrent rhinosinusitis is often prevalent in patients of RARS due to abundance of anatomical variants in the OMC region. DNS or ethmoid bulla when gets associated with concha bullosa increased the incidence of RARS. Present analysis would help surgeons to evaluate RARS patients for selective endoscopic sinus surgery

Antiulcer and Anti-inflammatory Activity of Aerial Parts Enicostemma littorale Blume

The antiulcer and in vitro anti-inflammatory activities of the aerial parts of Enicostemma littorale against aspirin, ethanol, and pyloric ligation-induced ulcers in rats and bovine serum albumin denaturation were studied. The extract (200 mg/kg and 400 mg/kg po) was administered to the overnight fasted rats, one hour prior to aspirin / alcohol / pyloric ligation challenge. The ulcer index, tissue GSH levels, and lipid peroxidation levels were estimated in all the models of ulcers and the volume of gastric secretion, acidity, and pH, were estimated in the pyloric ligation model of ulcers. Pretreatment with the extract showed a dose-dependent decrease in the ulcer index (Against Aspirin, ethanol challenge, and pyloric ligation. The prior administration of the extract also reduced the total acidity, free acidity, and volume of gastric secretion, and elevated the gastric pH. In addition, it was also observed that the extract inhibited the serum albumin denaturation in a dose-dependent manner. It may be concluded that the methanolic extract possesses antiulcer activity, and the anti-inflammatory activity of the extract may be attributed to the antioxidant potential, as reported earlier

Fundamental understanding and modeling of spin coating process : A review

A mathematical model is derived to elucidate the dominant mechanism governing film formation. It leads to a relation between film thickness and film radius spreading with time. Inclusion of evaporation and shear stress was made with extension to non-Newtonian fluid. The advantages and disadvantages of this process with applications are reviewed.Niranjan Sahu*, B Parija and S Panigrahi Department of Physics, National Institute of Technology, Rourkela-769 008, Orissa, India E-mail : [email protected] of Physics, National Institute of Technology, Rourkela-769 008, Orissa, Indi

AntI-Inflammatory Triterpene Saponins of Pzthecellobium Dulce: Characterization of an Echinocystic Acid Bisdesmoside

A new bisdesmodic triterpenoid saponin, dulcin was isolated from the seeds of Pithecellobium duke and was identified as 3-O-[j-D-ghEopyranosyl (1+2)-r-L-arabinopyranosyl]-28-O-[~-D-xylopyranosyI (l-,6)-B-D-glucopyranosyll- echinocystic acid. The known oleanolic acid saponin P,, oleanolic acid 3-O-fi-D-glucopyranosyl (1 -+2)-Z-Larabinopyranoside was also obtained. The structural features were elucidated by a combination of spectroscopic methods and some chemical transformations

Bayesian analysis of high-resolution ultrasonography and guided fine needle aspiration cytology in diagnosis of palpable thyroid nodules

Abstract Introduction To evaluate diagnostic accuracy of high-resolution ultrasonography in differentiation of benign and malignant thyroid nodules in comparison to results of guided fine needle aspiration cytology based on the Bayes rule. Objective To assess the validity of ultrasonography results of thyroid nodules in comparison to guided fine needle aspiration cytology findings. Methods This study was done on randomly chosen 80 patients presented with palpable thyroid nodules, undergone real-time sonographic evaluation of thyroid nodules to characterize features, internal consistency, margins, echotexture, calcification, peripheral lucent halo and vascularity. Ultrasonography guided fine needle aspiration cytology studies of thyroid nodules were done. Results Palpable thyroid nodules were highly prevalent in fourth and fifth decades of life with female-male ratio, 4:1. Solid internal consistency was demonstrated by 75% malignant nodules. Hypoechogenicity and intra-nodular micro-calcifications were observed in 92% malignant nodules; 83% malignant nodules had intra-nodular vascularity and absence of peripheral halo. The pre-test prevalence of malignant nodules in the targeted population was 17.5%. As type I error, 2.5% false-positive cases and as type II error, 5.0% false-negative cases were detected. Values of sensitivity and specificity of the ultrasonography test were 71.43 and 96.97%, respectively. Conclusion Malignant thyroid nodules demonstrated ultrasonography characteristics of hypoechoic texture, intra-nodular micro-calcifications, solid consistency, internal vascularity and absence of peripheral halo. The ultrasonography test has 92.5% diagnostic accuracy to differentiate malignant from benign lesions in comparison to the gold standard fine needle aspiration cytology test