Perturbed spherical objects in acoustic and fluid flow fields

In this study, the time averaged acoustic radiation force and drag on a small, nearly spherical object suspended freely in a stationary sound wave field in a compressible, low viscosity fluid is to be calculated. This problem has been solved for a spherical object, and it has many important engineering applications related to segregation and separation processes for particles in fluids such as water. Small but significant errors have occurred in the predicted behavior of the particles using the existing approximate solutions based on perfect spheres. The classical approach has been extended in this research to objects that deviate slightly from spherical shape whose boundary may be expressed in the general form, in spherical coordinates rp = a{1 + εδ(θ, φ)} where a is the radius of an unperturbed sphere, |ε|\u3c\u3c 1 is a small radius variation parameter and δ(θ, φ) is a smooth, perturbation function, π -periodic in θ and 2π - periodic in φ, chosen such that |δ| = 0(1) and |εδ(θ,φ)| \u3c 1 : 0 ≤ θ ≤ π, \u3c 0 ≤ φ ≤ 2π A simple and straightforward method for treating the scattering problem of an irregular shaped nearly spherical object is presented. Detailed calculations are carried out to estimate the contributions to the acoustic and drag forces generated by the perturbations in shape to the first order in the small parameter E. A mathematical model is developed to calculate trajectories of perturbed particles due to application of acoustic standing waves. The resulting system of second order ordinary differential equations does not have a closed form solution, and it is so stiff that it is even difficult to solve numerically. A combination of phase space and asymptotic analysis turns out to be far more useful in obtaining approximate solutions. Analysis of the solutions shows that all particles move towards the pressure node to first order in ε. Moreover, it is found that the first order correction term tend to be several orders of magnitude larger than the zeroth order terms, which is an indication of their importance in the analysis of the particle dynamics

Multispeciality Approach in the Management of Patient with Hereditary Gingival Fibromatosis: 1-Year Followup: A Case Report

Background. Hereditary gingival fibromatosis is a fibrotic enlargement of the gingiva. It may exist as an isolated abnormality or as part of multisystem syndrome. This paper reports a case of 16-year-old male with generalized severe gingival overgrowth, involving the maxillary and mandibular arches and covering almost all teeth. Methods. Periodontal management of gingival enlargement included gingivectomy in both arches except in the lower right molar region where flap surgery was done under general anesthesia. After a 2-month followup period, orthodontic treatment was started with fixed appliances. Monthly periodontal checkups and maintainance (scaling and polishing) were scheduled to control the gingival inflammation. Results. Reevaluation of the patient of surgical treatment after two months did not show any recurrence of condition; however, minimal overgrowth was noted 1 month after the beginning of orthodontic treatment which was treated nonsurgically. Conclusions. Although the risk of recurrence is high with this condition, surgical treatment with correction of malocclusion and regular followup can provide excellent outcome as seen in this case

Presacral immature teratoma with carcinoid in a young adult male: A rare case presentation

Presacral region is defined as potential space delineated by the rectum anteriorly, sacrum posteriorly, peritoneal reflection superiorly, and perineal muscles inferiorly. Tumors within the presacral space are uncommon with an incidence of 1:40,000. Presacral teratomas in adults are very rare. We, herein, present a case of 39‑year‑old male who was admitted with chief complaint of per rectal bleed. A large presacral mass was present which on histopathological examination was found to be immature teratoma with neuroendocrine differentiation

How uniform is donor history questionnaire for screening potential blood donors: a critical analysis

Background: Transfusion of whole blood or blood products are a clinical necessity in numerous clinical conditions. Blood donated from healthy human volunteers is the only method currently available to acquire blood transfusion and production of blood products. Donor history questionnaire (DHQ) contributes immensely to ensure safe blood donation. The aim was to compare the donor history questionnaire for blood donation deferral of various regions and organizations with that of World Health Organization (WHO).Methods: An extensive internet search for donor history questionnaires (DHQ) for blood donation deferral of different regions, countries and organization was conducted. Seven such forms were found which could be downloaded. A critical analysis of these forms was conducted based on history pertaining to use of medicines, disease history or procedure undergone recently. A comparative analysis was conducted finally with the World Health Organization (WHO) recommendations on the issue of donor screening and deferral. Descriptive analysis was done for comparison of donor history questionnaires in regards to drugs taken, disease history and invasive procedures performed.Results: After the analysis of the DHQs, we found that despite many similarities, there were significant differences in the questionnaires. The differences were more with respect to questions asked about the medicines, both traditional as well as modern.Conclusions: DHQs analysed by us revealed wide variations in their enquiry from potential donors about exposure to prescription medicines as well as the disease history. A suggestion is that more questions related to alternative medicines, nutraceuticals and other similar xenobiotic should be included

Can preterm birth be gainfully prevented?

Background: Preterm birth is a major cause of perinatal deaths and a significant cause of long-term loss of human potential amongst survivors all around the world. Complications of preterm birth are the single largest direct cause of neonatal deaths, responsible for 35% of the world’s 3.1 million deaths a year, and the second most common cause of under-5 deaths after pneumonia. In almost all high and middle income countries of the world, preterm birth is a leading cause of child death. The effect of preterm birth amongst some survivors may continue throughout life, impairing neuro-developmental functioning through increasing the risk of cerebral palsy, learning impairment and visual disorders and affecting long term physical health with a higher risk of non-communicable diseases. Premature infants have to deal with variety of problems including almost every system of body. Hence the preterm birth is one of the largest single conditions in the global burden of disease analysis given in the high mortality and the considerable risk of lifelong impairment.Methods: The present study was conducted on 100 patients admitted with spontaneous preterm labour with effect from November 2012 to March 2014. The risk factors leading to preterm labour were evaluated along with mode of delivery and neonatal outcome. The purpose of the study was to evaluate the need and success of various monitoring procedures and interventional strategies if they could improve the gestational age and gestational weight to improve perinatal outcome. The neonatologist joined in this study in providing neonatal care to reduce morbidities in these high risk preterm babies.Results: The data was evaluated and significant prolongation of pregnancy in preterm cases was achieved by optimization of preterm births by appropriate management.Conclusions: Identification of various risk factors leading to preterm labour and their proper management at tertiary care centre can improve the neonatal survival

Dermatofibrosarcoma protuberans of breast - A case report

Dermatofibrosarcoma protuberans (DFSP) is best regarded as well differentiated, primary fibrosarcoma of skin. It is an uncommon, slow growing, locally aggressive, and reoccurring but rarely metastasizing tumor of the deep dermis and subcutaneous tissue. Clinically they present as firm solid nodules that arise most frequently on trunk and extremities. DFSP of the breast has been rarely reported. Here, we report a rare case of DFSP of the breast in 47-year-old woman

Studies on thermoluminescence parameters of erbium doped Y2O3 nanophosphors

The thermoluminescence (TL) glow curve of Y2O3:Er3+ with different radiation time has been studied. The experimental glow curve shows the presence of two peaks at linear heating rate 10°C/min. The activation Energy and frequency factor are determined by thermoluminescence glow curve