An investigation on molecular dynamics of binary mixtures of N-methylacetamide and tetramethylurea in microwave region

The dielectric relaxation times (τ)and the dipole moments (µ) of the binary mixtures of different molar concentrations of tetramethylurea (TMU) in the binary mixtures of N-methylacetamide (NMA) and tetramethylurea (TMU) in benzene solutions have been calculated by using standard standing wave microwave techniques and Gopala Krishna’s single frequency (9.90 GHz) concentration variational method at different temperatures (25 °C, 30 °C, 35 °C and 40 °C). The energy parameters (He, Fe, Se) for the dielectric relaxation process of binary mixtures containing 30% mole-fraction of TMU have been calculated at the respective given temperatures and the comparison has been made with the corresponding energy parameters (Hη, Fη, Sη) for the viscous flow. On the basis of the observations, it is found that the dielectric relaxation process can be treated as the rate process like the viscous flow process. The solute-solute and solute-solvent types of the molecular associations have been predicted

Topological phases and topological entropy of two-dimensional systems with finite correlation length

We elucidate the topological features of the entanglement entropy of a region in two dimensional quantum systems in a topological phase with a finite correlation length $\xi$. Firstly, we suggest that simpler reduced quantities, related to the von Neumann entropy, could be defined to compute the topological entropy. We use our methods to compute the entanglement entropy for the ground state wave function of a quantum eight-vertex model in its topological phase, and show that a finite correlation length adds corrections of the same order as the topological entropy which come from sharp features of the boundary of the region under study. We also calculate the topological entropy for the ground state of the quantum dimer model on a triangular lattice by using a mapping to a loop model. The topological entropy of the state is determined by loop configurations with a non-trivial winding number around the region under study. Finally, we consider extensions of the Kitaev wave function, which incorporate the effects of electric and magnetic charge fluctuations, and use it to investigate the stability of the topological phase by calculating the topological entropy.Comment: 17 pages, 4 figures, published versio

SUSTAINED RELEASE MICROBEADS OF RITONAVIR: IN VITRO AND IN VIVO EVALUATION

Objective: The main aim of the present investigation was to develop sustained release microbeads of ritonavir that has a shorter half-life (3-5 h) and requires twice a day administration. These formulations exhibit a sustained release of ritonavir that would expect to improve the therapy, better drug utilization, and patient compliance. Methods: Gellan-chitosan and calcium chloride reinforced beads of ritonavir were prepared by ionotropic gelation method employing different concentrations of gellan, chitosan, calcium chloride and drug. The prepared beads were evaluated for various physicochemical parameters such as particle size determination, drug entrapment efficiency, swelling studies, infrared spectroscopy study, differential scanning calorimetry, x-ray diffraction analysis, scanning electron microscopy, in vitro drug release study and in vivo bioavailability studies. Results: From the results, formulation GC-II exhibited higher drug entrapment efficiency (79.65±0.012), higher swelling index, sustained drug release over a period of 24 h, increased oral bioavailability (2.07 times higher than that of pure drug) and decreased elimination rate (2.15 times lesser for ritonavir microbeads) with prolonged elimination half-life (2.15 times more than pure drug) as compared to pure drug. Conclusion: Ritonavir microbeads have demonstrated as a better delivery system for the sustained release of the drug; which may in turn circumvent the drawbacks associated with the conventional therapy

Idiopathic multilocular thymic cyst-an incidental anterior mediastinal mass

Acquired thymic cyst are multilocular and they occur de novo or in association with mediastinal neoplasm, systemic autoimmune diseases and trauma. Here, we report a case of acquired multilocular thymic cyst due to non-specific inflammatory etiology in a 42-year old gentleman and our approach to diagnosis and management of anterior mediastinal mass. With no specific clinical symptom, he was diagnosed with anterior mediastinal mass incidentally by imaging studies. Definitive diagnosis of multilocular thymic cyst was obtained by tissue diagnosis of the anterior mediastinal mass resected during the surgery

Thermal oxidation of Ti6Al4V alloy: Microstructural and electrochemical characterization

Thermal oxidation (TO) of Ti6Al4V alloy was performed at 500, 650 and 800 ◦C for 8, 16, 24 and 48 h in air. The morphological features, structural characteristics, microhardness and corrosion resistance in Ringer’s solution of TO Ti6Al4V alloy were evaluated and compared with those of the untreated one. The surface morphological features reveal that the oxide film formed on Ti6Al4V alloy is adherent to the substrate at 500 and 650 ◦C irrespective of the oxidation time whereas it spalls off when the alloy is oxidized at 800◦C for more than 8 h. X-ray diffraction (XRD) measurement reveals the presence of Ti(O) and -Ti phases on alloy oxidized at 500 and 650◦C, with Ti(O) as the dominant phase at 650◦C whereas the alloy oxidized at 800◦C exhibits only the rutile phase. Almost a threefold increase in hardness is observed for the alloy oxidized at 650 ◦C for 48 h when compared to that of the untreated one. Thermally oxidized Ti6Al4V alloy offers excellent corrosion resistance in Ringer’s solution when compared to that of the untreated alloy

Generating Evidence From Contextual Clinical Research in Low- to Middle Income Countries: A Roadmap Based on Theory of Change

Along with inadequate access to high-quality care, competing health priorities, fragile health systems, and conflicts, there is an associated delay in evidence generation and research from LMICs. Lack of basic epidemiologic understanding of the disease burden in these regions poses a significant knowledge gap as solutions can only be developed and sustained if the scope of the problem is accurately defined. Congenital heart disease (CHD), for example, is the most common birth defect in children. The prevalence of CHD from 1990 to 2017 has progressively increased by 18.7% and more than 90% of children with CHD are born in Low and Middle-Income Countries (LMICs). If diagnosed and managed in a timely manner, as in high-income countries (HICs), most children lead a healthy life and achieve adulthood. However, children with CHD in LMICs have limited care available with subsequent impact on survival. The large disparity in global health research focus on this complex disease makes it a solid paradigm to shape the debate. Despite many challenges, an essential aspect of improving research in LMICs is the realization and ownership of the problem around paucity of local evidence by patients, health care providers, academic centers, and governments in these countries. We have created a theory of change model to address these challenges at a micro- (individual patient or physician or institutions delivering health care) and a macro- (government and health ministries) level, presenting suggested solutions for these complex problems. All stakeholders in the society, from government bodies, health ministries, and systems, to frontline healthcare workers and patients, need to be invested in addressing the local health problems and significantly increase data to define and improve the gaps in care in LMICs. Moreover, interventions can be designed for a more collaborative and effective HIC-LMIC and LMIC-LMIC partnership to increase resources, capacity building, and representation for long-term productivity.publishedVersio

Development, testing and plant trails of single reagent system for coal flotation

Flotation is an important means of upgrading the fine fraction of raw coal, typically particles finer than 0.5 mm. Due to increased use of highly mechanized mining techniques large quantities of fines (< 0.5 mm) are being generated. These fines presently account for approximately 20–30% of the total plant feed. More than 140 million tones of fine coals are beneficiated by flotation worldwide annually. In coal flotation, reagents are required to enhance the hydrophobicity of coal surface. In addition to hydrophobic character, the selectivity, proper froth structure, stability and less sensitive to water chemistry are important. Water insoluble hydrocarbons are widely used as collectors in coal flotation. These collectors are basically non-polar oils like diesel, kerosene, etc. along with some frothers. Thus, it is necessary to add collector and frother separately in coal flotation. It is generally accepted that in coal flotation a single reagent system is more advantageous than the present practice of two reagent system. National Metallurgical Laboratory is involved in the flotation of coal fines using alternative single collector systems to developed specially replace fuel oils and frothers. For this purpose NML has entered into an agreement with M/s Somu Organo-Chem Pvt. Ltd. (SOCPL) Bangalore, a leading reagent manufacturer. Under this collaboration M/s SOCPL developed reagents and NML evaluated their selectivity index and application in coal flotation. Among many reagents developed and evaluated one best reagent was selected and full scale plant trails were conducted. The paper deals with the results obtained with several reagents in the laboratory and the plant trails

A study on various clinical presentations of extradural hemorrhage, factors affecting treatment and early outcome

Background: In India 11% of deaths are due to trauma and 78% of injury deaths are due to head injury. The aim of this study was to analyse the clinical spectrum and to evaluate the postoperative outcome in patients with head injury with an extradural hematoma.Methods: This was a retrospective observational study which included 100 patients admitted in King George hospital, Andhra medical college, Visakhapatnam, Andhra Pradesh, India over the past two years (01/10/2014 to 30/09/2016) with head injury, diagnosed to have traumatic extradural hemorrhage. A detailed clinical history, physical examination and CT scan was performed in all patients. For patients who were subjected to surgery operative and post-operative findings were noted.Results: The maximum patients suffering from EDH are in the age group of 21-30 years (28%) with male predominance (95%). The most common mode of injury is RTA (58%) under the influence of alcohol. Majority of cases reached hospital within 6 hours from  time of injury (44%). 95% of patients with EDH presented with LOC followed by vomiting in 68% of cases, followed by Headache in 42% of cases. 53% of the cases presented with mass effect over brain parenchyma with frontal EDH as most common location. Out of 100 cases, surgical approach was considered in 57 patients while remaining 47 patients were managed conservatively. Recovery from clinical and functional morbidity was satisfactorily acceptable, following treatment.Conclusions: Early presentation with mild to moderate GCS has good clinical outcome with minimal disability

Asymmetry to symmetry transition of Fano line-shape: Analytical derivation

An analytical derivation of Fano line-shape asymmetry ratio has been presented here for a general case. It is shown that Fano line-shape becomes less asymmetric as \q is increased and finally becomes completely symmetric in the limiting condition of q equal to infinity. Asymmetry ratios of Fano line-shapes have been calculated and are found to be in good consonance with the reported expressions for asymmetry ratio as a function of Fano parameter. Application of this derivation is also mentioned for explanation of asymmetry to symmetry transition of Fano line-shape in quantum confined silicon nanostructures.Comment: 3 figures, Latex files, Theoretica

Classical open lumbar laminectomy and discectomy for disc herniations among manual labourers in India

Background: Lumbar disc herniations are most common at L4/5 and L5/S1 levels and this is most prevalent condition among manual laborers. The aim of the study to analyze the clinical presentation, age and sex distribution, immediate postoperative complications and long-term complications/recurrence of symptoms and to formulate recommendations to avoid complications and recurrence of symptoms.Methods: This is a retrospective study which includes 250 patients operated for lumbar disc herniations at L4/5 and L5/S1 levels. A detailed history of presenting complaints, clinical examination and corresponding findings on imaging are correlated. In all these patients, there was severe symptomatology with failed conservative management which necessitated classical open lumbar laminectomy and discectomy. These patients were followed for a period of 5 to 10 years.Results: Assessment of outcome was done using the modified Macnab criteria. The overall success rate was 96% in our series. Post operatively, 9.2% of them experienced localized low back pain which is mild to moderate and being treated with NSAIDS and exercises. 2.4% developed residual disc herniation or hypertrophic fibrotic scar at the operated site which needed surgical intervention. 2% developed spondylolysis and spondylolesthesis at the level of previous surgery, and 4.4% developed adjacent disc herniations.Conclusions: The overall success rate was 96% in our series. In addition to removal of herniated disc other compressing elements like hypertrophied Ligamentumflavum, facet arthropathy and narrowed spinal canal diameter are also addressed with open procedure. To prevent later complications, these patients are supposed to avoid strenuous work, lifting weights, torsion and jerky movements, faulty posture at work and rest, gait training, crouching, sitting on the floor and haunches