Large-eddy simulation of Rayleigh-B\'enard convection for extreme Rayleigh numbers

We adopt the stretched spiral vortex sub-grid model for large-eddy simulation (LES) of turbulent convection at extreme Rayleigh numbers. We simulate Rayleigh-B\'enard convection (RBC) for Rayleigh numbers ranging from $10^6$ to $10^13$ and for Prandtl numbers 0.768 and 1. We choose a box of dimensions 1:1:10 to reduce computational cost. Our LES yields Nusselt and Reynolds numbers that are in good agreement with the direct-numerical simulation (DNS) results of Iyer et al. (Proc. Natl. Acad. Sci., vol 117 (14), 2020, pp. 7594-7598), albeit with a smaller grid size and at significantly reduced computational expense. For example, in our simulations at $Ra = 10^13$, we use grids that are 1/120 times the grid-resolution as that of the DNS (Iyer et al., Proc. Natl. Acad. Sci., vol 117 (14), 2020, pp. 7594-7598). The Reynolds numbers in our simulations range from 1,000 to 200,000. Consistent with the literature, we obtain scaling relations for Nusselt and Reynolds numbers as $Nu \sim Ra^{0.322}$ and $Re \sim Ra^{0.502}$. We also perform LES of RBC with periodic side-walls, for which we obtain the corresponding scaling exponents as 0.343 and 0.477 respectively. Our LES is a promising tool to push simulations of thermal convection to extreme Rayleigh numbers, and hence enable us to test the transition to ultimate convection regime.Comment: 26 pages, 15 figures. Submitted to Journal of Fluid Mechanic

Tuberous sclerosis with visceral leishmaniasis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Visceral leishmaniasis, a tropical infectious disease, is a major public health problem in India. Tuberous sclerosis, a congenital neuro-ectodermosis, is an uncommon disease which requires life long treatment.</p> <p>Case presentation</p> <p>A 15-year-old Indian patient, presented to the outpatient department of our institute with a high-grade fever for two months, splenomegaly and a history of generalized tonic-clonic convulsions since childhood. The clinical and laboratory findings suggested visceral leishmaniasis with tuberous sclerosis. The patient was treated with miltefosine and antiepileptics.</p> <p>Conclusion</p> <p>The patient responded well and in a follow up six months after presentation, she was found free of visceral leishmaniasis and seizures. Diagnosis and treatment of this rare combination of diseases is difficult.</p

In vitro anti-HIV activity of some Indian medicinal plant extracts

Background Human Immunodeficiency Virus (HIV) persists to be a significant public health issue worldwide. The current strategy for the treatment of HIV infection, Highly Active Antiretroviral Therapy (HAART), has reduced deaths from AIDS related disease, but it can be an expensive regime for the underdeveloped and developing countries where the supply of drugs is scarce and often not well tolerated, especially in persons undergoing long term treatment. The present therapy also has limitations of development of multidrug resistance, thus there is a need for the discovery of novel anti-HIV compounds from plants as a potential alternative in combating HIV disease. Methods Ten Indian medicinal plants were tested for entry and replication inhibition against laboratory adapted strains HIV-1IIIB, HIV-1Ada5 and primary isolates HIV-1UG070, HIV-1VB59 in TZM-bl cell lines and primary isolates HIV-1UG070, HIV-1VB59 in PM1 cell lines. The plant extracts were further evaluated for toxicity in HEC-1A epithelial cell lines by transwell epithelial model. Results The methanolic extracts of Achyranthes aspera, Rosa centifolia and aqueous extract of Ficus benghalensis inhibited laboratory adapted HIV-1 strains (IC80 3.6–118 μg/ml) and primary isolates (IC80 4.8–156 μg/ml) in TZM-bl cells. Methanolic extract of Strychnos potatorum, aqueous extract of Ficus infectoria and hydroalcoholic extract of Annona squamosa inhibited laboratory adapted HIV-1 strains (IC80 4.24–125 μg/ml) and primary isolates (IC80 18–156 μg/ml) in TZM-bl cells. Methanolic extracts of Achyranthes aspera and Rosa centifolia, (IC801-9 μg/ml) further significantly inhibited HIV-1 primary isolates in PM1cells. Methanolic extracts of Tridax procumbens, Mallotus philippinensis, Annona reticulate, aqueous extract of Ficus benghalensis and hydroalcoholic extract of Albizzia lebbeck did not exhibit anti-HIV activity in all the tested strains. Methanolic extract of Rosa centifolia also demonstrated to be non-toxic to HEC-1A epithelial cells and maintained epithelial integrity (at 500 μg/ml) when tested in transwell dual-chamber. Conclusion These active methanolic extracts of Achyranthes aspera and Rosa centifolia, could be further subjected to chemical analysis to investigate the active moiety responsible for the anti-HIV activity. Methanolic extract of Rosa centifolia was found to be well tolerated maintaining the epithelial integrity of HEC-1A cells in vitro and thus has potential for investigating it further as candidate microbicide

Anti-inflammatory Components from Functional Foods for Obesity

Obesity, defined as excessive fat accumulation that may impair health, has been described throughout human history, but it has now reached epidemic proportions with the WHO estimating that 39% of the world’s adults over 18 years of age were overweight or obese in 2016. Obesity is a chronic low-grade inflammatory state leading to organ damage with an increased risk of common diseases including cardiovascular and metabolic disease, non-alcoholic fatty liver disease, osteo-arthritis and some cancers. This inflammatory state may be influenced by adipose tissue hypoxia and changes in the gut microbiota. There has been an increasing focus on functional foods and nutraceuticals as treatment options for obesity as drug treatments are limited in efficacy. This chapter summarises the importance of anthocyanin-containing fruits and vegetables, coffee and its components, tropical fruit and food waste as sources of phytochemicals for obesity treatment. We emphasise that preclinical studies can form the basis for clinical trials to determine the effectiveness of these treatments in humans

External Jugular Vein Aneurysm with Thrombus Presenting as Painful Neck Mass: A Case Report

Abstract External jugular vein aneurysm with thrombosis presenting as neck swelling is a rare clinical entity and rarely encountered in routine clinical practice. We present a case of a 45-year-old female with external jugular vein aneurysm presenting as a painful lump in the neck. Ultrasound of the neck and CT angiography showed saccular dilation of the lower end of the external jugular vein with thrombosis within the aneurysm. Saccular aneurysm of the external jugular vein is very uncommon and can lead to thrombotic complications with serious consequence

Pits and pearls in the management of giant goiters

Objective: Giant goiters invariably have been neglected by the patients allowing them to grow to huge sizes. Usually, these are slow growing and are not troublesome, and hence, the patients ignore them. The treatment of such goiters is surgery. However, when these become >10 cm, they pose challenges to the patient, the anesthetist, and foremost the surgeon. Materials and Methods: We present here a single-institutional experience of managing 13 monster goiters. Harmonic scalpel and bipolar cautery were used intraoperatively. The surgical loupes were used in all cases for identification of the nerves. Their clinical presentation, salient symptoms and our experience, and key factors affecting successful outcomes were analyzed. Results: Ten patients had benign lesion and three harbored malignancy. All patients were made euthyroid before surgery except one in whom the indication for surgery was thyrotoxicosis. All patients underwent awake fiber-optic intubation. Four patients underwent total thyroidectomy, two underwent hemithyroidectomy, and remaining underwent subtotal thyroidectomy. One patient required sternotomy for retrosternal extension of the goiter. Harmonic scalpel and bipolar cautery were used intraoperatively. Surgical loupes were used in all cases for identification of the nerve. In all cases, recurrent laryngeal nerve was identified. Tracheomalacia was noted in two patients, and only one of them had to be tracheostomized postoperatively. Conclusion: Anatomy was found to be distorted in all our cases. Identifying the nerve was difficult due to distorted anatomy. Transient hypocalcemia was a consistent feature in spite of identifying the parathyroids and preserving its blood supply. Cases with tracheomalacia and bilateral vocal cord palsy can pose challenge for extubation, and tracheostomy needs to be considered in them

Metastatic papillary carcinoma thyroid co-existing with oral cavity squamous cell carcinoma: A case report and review of literature

AbstractThe incidental discovery of metastatic papillary carcinoma thyroid in lymph node while the patient is being investigated for primary squamous cell carcinoma of the oral cavity is an unusual clinical situation and the appropriate management in such clinical situation is controversial and confusing. We report a case of a 65year old male with primary squamous cell carcinoma of alveolus with bilateral neck nodes. Fine needle aspiration cytology showed metastatic squamous cell carcinoma in lymph nodes on the left side and metastatic papillary carcinoma in the lymph node on the right side. We present the diagnostic dilemma and the confusion in planning the treatment of such difficult situation

Large central osteoma of maxillary sinus: A case report

AbstractOsteoma is a benign osteogenic tumor arising from the proliferation of compact or cancellous bone. Osteomas of the craniofacial region are common in the nose and paranasal sinus particularly in the frontoethmoid region. However osteoma of the maxillary antrum is very rare and its presentation is different from the commoner frontoethmoid osteomas. We present here a rare case of large osteoma of the maxillary antrum in a 12-year-old child and also describe the difficulty faced in removing the tumor endoscopically. The tumor was removed using combined approach

Saccular cyst – Cause of intermittent stridor in a child: A case report

Saccular cyst is a rare lesion of larynx causing respiratory obstruction and stridor in neonates and infants. Herein we present a case of a 4 year old who presented to us with intermittent respiratory distress and stridor. Fibreoptic bronchoscopy showed the presence of saccular cyst overhanging the anterior part of right vocal cord. Endoscopic marsupialization of cyst is done using laryngeal microdebrider with stripping of cyst lining. Saccular cyst should be considered in the differential diagnosis of children presenting with intermittent stridor