Monte Carlo Simulation of Smectic Liquid Crystals and the Electroclinic Effect: the Role of the Molecular Shape

Using Monte Carlo simulation methods, we explore the role of molecular shape in the phase behavior of liquid crystals and the electroclinic effect. We study a "bent-rod" mesogen shaped like the letter Z, composed of seven soft spheres bonded rigidly together with no intra-molecular degrees of freedom. For strongly angled molecules, we find that steric repulsion alone provides the driving force for a smectic-C phase, even without intermolecular dipole-dipole interactions. For weakly angled (nearly rod-like) molecules, we find a stable smectic-A (SmA) phase and a strong electroclinic effect with a saturation tilt angle of about 19 degrees. In the SmA phase we find evidence of vortex-like point defects. We also observe a field-induced nematic-smectic phase transition.Comment: 10 pages, including 10 postscript figures, uses REVTeX 3.0 and epsf.st

Orientational order in anisaldazine in the nametic phase

The refractive indices of anisaldazine, CH3OC6H4CH:NN:CHC4H4OCH3, have been measured in the crystalline, nematic and isotropic phases and the orientational order parameter in the mesophase has been evaluated by the application of the Vuks formula. The curve for the order parameter versus the relative temperature (Te-T) is nearly parallel with those for p-azoxyanisole and p-azoxyphenetole and lies approximately midway between them

Retrospective study of chemotherapy induced cardiotoxicity from a tertiary cancer centre in South India

Background: Ever increasing therapeutic modalities in treatment of various malignancies has resulted in an enormous number of cancer survivors. Cancer survivors face various issues in their long term health due to the cancer and/or its treatment. Late effects including organ damage, functional disability and risk of second malignancy continue to be elucidated. One of the most debilitating and serious toxicity is cardiotoxicity due to chemotherapy.Methods: This study was a retrospective analysis of all patients who developed chemotherapy induced cardiotoxicity between January 2013 to December 2015.Results: A total of 16 patients developed cardiotoxicity. 13 patients had doxorubicin induced toxicity. Cardiotoxicity was noted to occur at low cumulative doses. 2 patients had complete recovery of left ventricular ejection fraction (LVEF) on follow up. 1 patient had progressive worsening of LVEF. 1 patient died due to cardiotoxicity. On detection of cardiotoxicity, most of the patients received cardiac remodeling drugs - angiotensin converting enzyme inhibitors (mostly enalapril), other drugs used were carvedilol and diuretics.Conclusions: In Indian patients, cardiotoxicity can occur at very low cumulative doses of doxorubicin and in young patients too. Most of the patients did not have any underlying comorbid illnesses. We wish to highlight the need to diligently repeat cardiac screening investigations at frequent intervals to detect asymptomatic cardiotoxicity

A Study Comparing the Efficacy of Ondansetron, Palenosetron and Aprepitant in the Prevention of Chemotherapy induced Nausea and Vomiting in Breast Cancer patients receiving Moderately Emetogenic Chemotherapy.

Introduction: Nausea and vomiting are the most feared complications of chemotherapy experienced By the patients.1,2.Almost 70-80% of all cancer patients will be having chemotherapy induced Nausea and vomiting.3,4 The prevention of chemotherapy induced nausea and vomiting (CINV) is Very much important and necessary because it has huge implications on both patient’s and Clinician’s perspective. As it is the most common problem faced by patients and as it can be Prevented or controlled to a certain extent with the judicious and careful use of anti emetics sums Up the significance of the need to select an appropriate anti emetic regimen for a particular class Of chemotherapy. Prevention is always better than cure ,which is an old age saying holds very true in the Perspective of CINV also because it is always important to prevent CINV rather than treat CINV As damage would have already occurred in the form of poor oral intake, affection of quality of Life , anxiety in the minds of patients ,creating doubts about their ability to tolerate further Chemotherapy thus leading to anticipatory vomiting in the subsequent cycles or loss of Compliance leading to inadequate treatment of the disease and last but not the least the financial Burden on the individual and the family for supportive care, hospital admission and the rescue Medications .5 Treatment of breast cancer also has undergone considerable improvement in the recent Times leading to increased chance of cure .Hence it becomes extremely important to provide the Cure with least toxicities and side effects of treatment. The chemotherapy used in breast cancer Patients falls under moderately emetogenic chemotherapy type (MEC) 6 . The choice of anti Emetic regimen in patients treated for highly emetogenic chemotherapy is clear and non Controversial. The same cannot be told about the anti emetic regimen in patients receiving MEC.7The development of newer anti emetic agents like palonosetron, aprepitant, fosaprepitant And casopitant has led to tremendous opportunities and improved patient care. Conventionally Ondansetron was the anti emetic of choice for patients receiving MEC but now with the advent of Aprepitant it is becoming the new standard of care as an antiemetic regimen of choice in patients Receiving MEC especially those receiving a combination of anthracycline and an alkylating Agent.7 There are only a few trials and studies using aprepitant in patients receiving MEC and in Fact there are no studies till date comparing palonosetron with aprepitant in the prevention of CINV in MEC. Hence our study is a sincere effort in that regard trying to compare palonosetron And aprepitant to ondansetron. And we also have compared palonosetron with aprepitant with Respect to their efficacies in the prevention of CINV .This will be of great help to a limited Resource country like ours, where a cheaper alternative can be of great relief to the patient Herself/himself and also to the treating centres and also will have great financial implications If a Cheaper alternative is obtained. AIM: PRIMARY OUTCOME To compare the Complete response rates in the ondansetron, palonosetron and Aprepitant based antiemetic prophylaxis regimen in patients of breast cancer patients Receiving moderately emetogenic chemotherapy SECONDARY OUTCOMES To determine the complete response during the acute phase after initiation of Chemotherapy To determine the complete response during the delayed phase after initiation of Chemotherapy To determine the impact of CINV on quality of life using the Functional living Index- Emesis(FLIE) scores in each of the 3 arms To determine the effect of antiemetic agents on the reduction of usage of rescue Medication

Posterior reversible encephalopathy syndrome in cancer patients: experience from a tertiary cancer center, South India

Posterior Reversible Encephalopathy Syndrome (PRES) is characterized by seizures, headaches, altered mental status, cortical blindness and typical transient lesions on MRI. PRES may be associated with chemotherapy, molecular targeted drugs and immunosuppressive agents used in patients with cancer. PRES is a very rare condition in cancer patients. PRES is usually reversible with appropriate supportive care and most patients can be restarted with treatment

Retinoblastoma – pattern, presentation and management: a quintessential experience of 5 years

Background: Retinoblastoma (RB) is the most common intraocular malignancy of childhood. It accounts for 10-15% of cancers that occur in infants. Objective of the study was to determine the pattern, presentation and management of Retinoblastoma (RB) patients at a tertiary cancer care center in South India, during a period of 5 years (1st November 2009 to 1st December 2014).Methods: This study was a retrospective analysis of the medical records of patients diagnosed as having retinoblastoma obtained from hospital information system and our cancer registry. Data sought was demographic characteristics, clinical presentation, investigations done, the methods of management and the treatment outcome of retinoblastoma patients.Results: Total number of cases studied was 31 and total number of eyes studied was 47. Out of 31 cases, 58% were female. 52% had bilateral involvement. The median age at presentation was 24 months. The commonest mode of presentation was leukocoria (55%) followed by proptosis (22%). Out of 47 eyes studied, 87% were advanced tumours belonging to Group D or Group E. Metastasis to the central nervous system was noted in 22.6% patients belonging to either Group D or Group E. Out of the 31 patients, 64.6% patients underwent enucleation. 6 out of 31 cases succumbed to death.Conclusions: Retinoblastoma continues to be a challenge in developing countries. Lack of awareness and inaccessibility to proper healthcare facilities are major stumbling blocks in achieving high cure rates. Educating the public and healthcare professionals, importance of early diagnosis and prompt referral are vital in reducing morbidity and mortality associated with the disease