Latin America 2040 — Breaking Away from Complacency: An Agenda for Resurgence

Latin America

Latin America 2040 — Breaking Away from Complacency: An Agenda for Resurgence

Latin America

Metallic monoclinic phase in VO2_2 induced by electrochemical gating: in-situ Raman study

We report in-situ Raman scattering studies of electrochemically top gated VO$_2$ thin film to address metal-insulator transition (MIT) under gating. The room temperature monoclinic insulating phase goes to metallic state at a gate voltage of 2.6 V. However, the number of Raman modes do not change with electrolyte gating showing that the metallic phase is still monoclinic. The high frequency Raman mode A$_g$(7) near 616 cm$^{-1}$ ascribed to V-O vibration of bond length 2.06 \AA~ in VO$_6$ octahedra hardens with increasing gate voltage and the B$_g$(3) mode near 654 cm$^{-1}$ softens. This shows that the distortion of the VO$_6$ octahedra in the monoclinic phase decreases with gating. The time dependent Raman data at fixed gate voltages of 1 V (for 50 minute, showing enhancement of conductivity by a factor of 50) and 2 V (for 130 minute, showing further increase in conductivity by a factor of 5) show similar changes in high frequency Raman modes A$_g$(7) and B$_g$(3) as observed in gating. This slow change in conductance together with Raman frequency changes show that the governing mechanism for metalization is more likely to the diffusion controlled oxygen vacancy formation due to the applied electric field.Comment: 5 pages, 6 figure

Increased resistance to Nalidixic acid and Ciprofloxacin in Salmonella isolates from the Sub Himalayan region

Background: During the last two decades, increased resistance to nalidixic acid and ciprofloxacin has become a cause of global concern. The present study was undertaken to ascertain nalidixic acid and ciprofloxacin resistance in Salmonella isolates from our region. To know the true pattern of ciprofloxacin resistance by determining the minimum inhibitory concentration (MIC) through E-test.Methods: All the Salmonella isolates recovered from blood cultures were screened for nalidixic acid resistance using 30µg disc by the Kirby Bauer disc diffusion method. Ciprofloxacin susceptibility was done both by disc diffusion and MIC using CLSI breakpoints.Results: We analysed a total of 80 Salmonella isolates during the last three years. Salmonella enterica serovar Typhi was the predominant serovar in 51 (64.8%) isolates, followed by Salmonella enterica serovar Paratyphi A comprising 28 (36.2%) isolates. Amongst the total isolates 78 (97.5%) were nalidixic acid resistant. Of these 54 (67.5%) showed intermediate susceptibility and 9 (11.2%) were ciprofloxacin resistant by the disc diffusion technique. On the contrary 29 (36.2%) had decreased susceptibility to ciprofloxacin; while a larger number 38 (47.5%) were detected resistant to ciprofloxacin on determination of MIC by the E-test.Conclusions: Screening for nalidixic acid acts as a surrogate marker to detect ciprofloxacin resistance. However, the true pattern of ciprofloxacin resistance can be determined by calculating the MIC by the E-test

Comparative efficacy of agomelatine versus sertraline in major depressive disorder in Himalayan region of India

Background: Depression, a major common affective disorder which carries excess mortality through suicide. Among various drug classes available SSRI’s are usually a choice, but many patients show inadequate response, residual symptoms or discontinue medication due to intolerable side effects. Disturbances of circadian rhythm function are an etiopathogenic hallmark of depression. The degree of circadian misalignment correlates with the severity of depression and circadian abnormalities may partially be a consequence of alterations in behavior and sleep patterns that accompany depression. Agomelatine an agonist acts on MT1 and MT2 receptors and antagonist of 5HT2c receptors contributes to its resynchronization of circadian rhythms, enhancement of dopaminergic and adrenergic input to the frontal cortex, induction of hippocampal neurogenesis, and ultimately, to its antidepressant effect.Methods: The study was randomized, prospective, comparative and interventional regarding the efficacy of therapy. Hundred consenting patients of MDD attending psychiatry OPD were screened for possible enrollment into group A(Agomelatine) and group B(Sertraline). Patients were assessed by semi-structured case recording form, DSM-IV- TR Criteria for major depressive episode, Hamilton Rating Scale for Depression (HAM-D) and Clinical Global Impressions for severity (CGI-S) at baseline and CGI for improvement (CGI-I), every two weeks interval and final assessment at 8 weeks.Results: Socio-demographic parameters like age and sex distribution, marital status, locality, family type, educational status, occupation and socio-economic class were comparable between two groups. Similarly baseline HAM-D and CGI-S values between the two groups were statistically non-significant. HAM-D, CGI-S and CGI-I values at eight weeks among the two groups were also statistically non-significant but in all three sertraline had decreased the values to a greater extent and showed a trend towards improvement.Conclusions: Both groups had shown significant decrease in scores of all scales i.e. HAM-D, CGI-S, and CGI-I at the end of 8th week as compared to baseline scores, indicating that the uses of agomelatine and sertraline have resulted in significant improvement in symptoms of patients of MDD and reinforcing there efficacy in treatment of MDD. No statistical difference was observed between two groups.

Human Papillomavirus DNA in LEEP Plume

Objective: This study was undertaken to determine the prevalence of human papillomavirus (HPV) in loop electrosurgical excision procedure (LEEP) plumes

Understanding the effect of stress hormones on ovarian cancer cells

Department of Cancer Systems Imaging Department of Gynecologic Oncology and Reproductive Medicinehttps://openworks.mdanderson.org/sumexp22/1022/thumbnail.jp

Anomalous Raman scattering from phonons and electrons of superconducting FeSe0.82_{0.82}

We report interesting anomalies in the temperature dependent Raman spectra of FeSe$_{0.82}$ measured from 3K to 300K in the spectral range from 60 to 1800 cm$^{-1}$ and determine their origin using complementary first-principles density functional calculations. A phonon mode near 100 cm$^{-1}$ exhibits a sharp increase by $\sim$ 5% in frequency below a temperature T$_s$ ($\sim$ 100 K) attributed to strong spin-phonon coupling and onset of short-range antiferromagnetic order. In addition, two high frequency modes are observed at 1350 cm$^{-1}$ and 1600 cm$^{-1}$, attributed to electronic Raman scattering from ($x^2-y^2$)to $xz$ / $yz$ $d$-orbitals of Fe.Comment: 19 pages, 4 figures, 1 tabl

Prediction and failure of anti-angiogenesis escape

Many clinical trials have demonstrated the benefit of anti-angiogenesis therapy in the treatment of gynecologic cancer. However, these benefits have often been in terms of progression-free rather than overall survival and in some cases, the magnitude of benefit demonstrated in the pivotal phase 3 trials has been disappointing when compared with the percentage of patients who responded in earlier phase 2 trials. Two potential explanations for this are the current inability to stratify patients according to chance of benefit and the development of resistance mechanisms within the tumor. In this article, we review the prediction of response and the proposed resistance and escape mechanisms involved in anti-angiogenesis therapy, including the up-regulation of alternative proangiogenic pathways, vascular co-option, and resistance to hypoxia. These insights may offer a personalized strategy for anti-angiogenesis therapy and help us to consider the best selection of other therapies that should be combined with anti-angiogenesis therapy to improve the outcome of patients with gynecologic cancer