Control of the Onset of Filamentation in Condensed Media

Propagation of intense, ultrashort laser pulses through condensed media like crystals of BaF$_2$ and sapphire results in the formation of filaments. We demonstrate that the onset of filamentation may be controlled by rotating the plane of polarization of incident light. We directly visualize filamentation in BaF_2 via six-photon absorption-induced fluorescence and, concomitantly, by probing the spectral and spatial properties of white light that is generated.Comment: To appear in Phys. Rev.

Euler buckling in red blood cells: An optically driven biological micromotor

We investigate the physics of an optically-driven micromotor of biological origin. A single, live red blood cell, when placed in an optical trap folds into a rod-like shape. If the trapping laser beam is circularly polarized, the folded RBC rotates. A model based on the concept of buckling instabilities captures the folding phenomenon; the rotation of the cell is simply understood using the Poincar\`e sphere. Our model predicts that (i) at a critical intensity of the trapping beam the RBC shape undergoes large fluctuations and (ii) the torque is proportional to the intensity of the laser beam. These predictions have been tested experimentally. We suggest a possible mechanism for emergence of birefringent properties in the RBC in the folded state

Study of evaluation of anti-inflammatory activity of macrolide antibiotics in rats: an experimental study

Background: Inflammation is a complex and dynamic condition in which many changes take place at the site of inflammation, as well as systemically. In general, inflammatory response acts to protect the host, but many times it goes unchecked with tissue destruction leading to a spectrum of inflammatory disorders. Anti-inflammatory drugs have long been used to treat spectrum of inflammatory conditions. Anti-inflammatory agents, in use today, though have efficacy, cause a variety of side effects causing major problems during their clinical use. Amongst newer approaches to treat inflammation, macrolides, the anti-bacterial agents, seem to be beneficial in decreasing the inflammation. Still there is much speculation about the anti-inflammatory activity of macrolide antibiotics. So, we planned this study to assess anti-inflammatory activity of macrolide antibiotics (erythromycin, roxithromycin, azithromycin, and clarithromycin) and to compare their anti-inflammatory activity with control and indomethacin (standard non-steroidal anti-inflammatory drugs).Methods: To assess anti-inflammatory activity of macrolides, we used acute (carrageenin-induced paw edema and turpentine oil-induced arthritis), as well as chronic model of inflammation (cotton pellet induced granuloma).Results: All the macrolides, i.e., erythromycin, roxithromycin, azithromycin and clarithromycin showed significant (p<0.05) anti-inflammatory activity in acute models of inflammation as compared to control group. However, macrolides showed insignificant activity as compared to indomethacin (acute and chronic models of inflammation) and as compared to control (chronic model of inflammation).Conclusions: This study shows macrolide antibiotics have anti-inflammatory activity in animal models of acute inflammation

Evaluation of antidepressant activity of ondansetron alone and in combination with fluoxetine-an experimental study

Background: Direct antagonism at 5HT3 receptor site may be associated with antidepressant activity as conventional antidepressants also possess affinity for central 5HT3 binding site. So in this study, an effort is made to investigate the antidepressant effect of ondansetron (OND), a selective 5HT3 antagonist, alone and in combination with fluoxetine (FLX).Methods: Acute and chronic models of Forced swimming test (FST), tail suspension test (TST), open field test (OFT) and mice brain serotonin estimation  by UV spectrophotometry were applied for the evaluation of antidepressant activity.Results: In FST and TST (acute and chronic models), ondansetron showed statistically significant antidepressant activity (p<0.05) as compared to control. The combination groups (OND 0.25 mg/kg + FLX 5mg/kg & OND 0.5 mg/kg + FLX 5 mg/kg) showed statistically significant antidepressant activity (p<0.05) as compared to fluoxetine (5 mg/kg) and ondansetron (0.25 mg/kg and 0.5 mg/kg) in FST and TST (acute and chronic models). Open field test in chronic study showed ondansetron (0.25 mg/kg and 0.5 mg/kg) increases number of central squares crossed as compared to control which is statistically significant (p<0.05). The combination group (OND 0.25 mg/kg + FLX 5 mg/kg) showed significantly increased (p<0.05) number of central squares crossed as compared to fluoxetine (5 mg/kg). The combination group (OND 0.5 mg/kg + FLX 5 mg/kg) showed significantly increased (p<0.05) brain serotonin compared to control, ondansetron (0.25 mg/kg and 0.5 mg/kg) and fluoxetine (5 mg/kg).Conclusions: Our study concludes that ondansetron alone and in combination with fluoxetine possesses significant antidepressant activity in animal models of depression

Carbamazepine induced toxic epidermal necrolysis in a patient of seizure disorder

Toxic epidermal necrolysis (TEN), also known as Lyell's syndrome, is a widespread life-threatening mucocutaneous disease where there is extensive detachment of the skin and mucous membrane. Many factors are involved in the aetiology of TEN, the most common being the adverse drug reactions. Here we report a case of TEN in a 12 year old female child who presented with fever and blisters all over her body after taking carbamazepine for uncontrolled generalised tonic-clonic seizure. This case has been reported to highlight the importance of using carbamazepine cautiously as this case shows the “probable” association between carbamazepine and TEN, which is a life threatening condition

Timely use of anti-snake venom improves maternal and fetal outcome: a case report

Snake bite is a common medical emergency and an occupational hazard in a rural population of India. Though it is uncommon in pregnancy, it is associated with poor maternal and fetal outcome. Early gestational age and delay in the treatment are the factors responsible for unfavorable prognosis. Here, we report a case of primigravida, aged 22 years, with 22 weeks of gestation presenting with a history of snake bite on the left frontal region of the face. While on anti-snake venom treatment, patient developed anaphylactic reaction. In spite of this, the maternal and the fetal outcome were good in this case

A study on the clinico-epidemiological profile and the outcome of snake bite cases in the tertiary care hospital

Background: Snake bite is a common medical emergency and an occupational hazard in India. It is also a major public health issue in rural India where farming is a major source of employment. Very few studies describe epidemiology of snake bite from India. Hence, this study was planned to collect information on various aspects of snake bite in a tertiary care hospital.Methods: A prospective observational study of 167 patients of snake bite and unknown bite carried out from September 1, 2012 to August 31, 2013.Results: Among a total 167 cases, majority were males (54.49%), aged between 20 and 40 years (38.92%). Most of the cases were laborers (61.67%) and farmers (17.36%). Peak incidence was observed during monsoon (64.67%). Bite mark was seen in 46.70% cases, upper extremity being common site (52.09%). Most cases were of vasculotoxic bite (65.26%) and few were of neurotoxic bite (19.76%). Major complications were respiratory failure (4.79%) and acute renal failure (1.8%). Average bite to needle time was 365 min. Bleeding & clotting time was raised in 44.03% & 35.19% cases, respectively. Average dose of anti-snake venom (ASV) required was 17.1 vials. Allergic reactions to ASV observed in 8.38% cases. Mean duration of hospital stay was 4.3 days. Recovery rate was 94.01% with three cases referred to higher center. Mortality rate was 2.39%.Conclusions: Our study highlights various aspect of snake bite cases and tries to find out ways to improve quality of life of patients, decrease mortality and morbidity and decrease economic burden on society

Stochastic analysis of different rough surfaces

This paper shows in detail the application of a new stochastic approach for the characterization of surface height profiles, which is based on the theory of Markov processes. With this analysis we achieve a characterization of the scale dependent complexity of surface roughness by means of a Fokker-Planck or Langevin equation, providing the complete stochastic information of multiscale joint probabilities. The method is applied to several surfaces with different properties, for the purpose of showing the utility of this method in more details. In particular we show the evidence of Markov properties, and we estimate the parameters of the Fokker-Planck equation by pure, parameter-free data analysis. The resulting Fokker-Planck equations are verified by numerical reconstruction of conditional probability density functions. The results are compared with those from the analysis of multi-affine and extended multi-affine scaling properties which is often used for surface topographies. The different surface structures analysed here show in details advantages and disadvantages of these methods.Comment: Minor text changes to be identical with the published versio