Statistical Mechanics of DNA Rupture: Theory and Simulations

We study the effects of the shear force on the rupture mechanism on a double stranded DNA. Motivated by recent experiments, we perform the atomistic simulations with explicit solvent to obtain the distributions of extension in hydrogen and covalent bonds below the rupture force. We obtain a significant difference between the atomistic simulations and the existing results in the iterature based on the coarse-grained models (theory and simulations). We discuss the possible reasons and improve the coarse-grained model by incorporating the consequences of semi-microscopic details of the nucleotides in its description. The distributions obtained by the modified model (simulations and theoretical) are qualitatively similar to the one obtained using atomistic simulations.Comment: 18 pages, 9 figures. Accepted in J. Chem. Phys. (2013). arXiv admin note: text overlap with arXiv:1104.305

PREPARATION, CHARACTERIZATION, AND OPTIMIZATION OF MEBENDAZOLE SPHERICAL AGGLOMERATES USING MODIFIED EVAPORATIVE PRECIPITATION IN AQUEOUS SOLUTION (EPAS)

Objective: Mebendazole is a popular benzimidazole class anthelmintic drug useful in the treatment of main infections of threadworms as well as other less common worm infections like whipworm, roundworm, and hookworm in adults and children over 2 y of age. It is poorly soluble in water resulting in poor absorption from the intestinal tract leading to a decrease in bioavailability. Moreover, Mebendazole has poor flowability due to the needle-shaped crystals. This work was carried out with the aim of increasing the flowability and solubility of Mebendazole. Methods: A 32 full factorial design was used to investigate the effect of the concentration of Mebendazole and the quantity of water as an external phase using evaporative precipitation into an aqueous solution. The prepared agglomerates were characterized for particle size distribution, shape, Hausner ratio, Carr’s index and % dissolved in 60 min (C60).   Results: The prepared agglomerates were found to be monodispersed. They also showed a decrease in the Hausner ration and Carr’s index, indicating improved flowability. Increase in C60 indicated that the agglomerates were found to have increased water solubility. Conclusion: Scanning Electron Microscopy showed that the agglomerates were spherical in shape. Fourier Transformed Infra-Red studies showed no chemical change in the prepared spherical agglomerates. Differential Scanning Calorimetry and X-ray diffraction studies showed an increase in amorphous characteristics of prepared spherical agglomerates. This method may be used for drugs with similar characteristics as Mebendazole

Biodiversity Conservation Through Urban Green Spaces: A Case Study of Gujarat University Campus in Ahmedabad

The present study deals with the phytodiversity of Gujarat University campus and the surrounding region which forms an important green space in the urban environment of Ahmedabad city in Gujarat state, India. The extensive field surveys were carried out in the vast study area during 2004 to 2006 covering four different seasons viz. summer, winter, monsoon and spring to cover annual, biennial and perennial plants. A total of 451 species of flowering plants belonging to 338 genera and 101 families were recorded in the study area. Along with these three pteridophytes, two gymnosperms and the algae and fungi group appearing mostly in the monsoon season were also recorded in the study. Among the flowering plants, the herbs were found to be dominant, indicating they favored the climatic factors like less rainfall and high temperature in the study area. Raunkier’s biological life forms revealed the dominance of therophytes and phanerophytes, indicating ‘Thero-Phanerophytic’ phytoclimate in the region. The urban green spaces with such rich plant diversity need to be conserved, especially with the help of the local population, in order to maintain a good environment and biodiversity, thereby improving the overall quality of life

Work and Quantum Phase Transitions: Is there Quantum Latency?

We study the physics of quantum phase transitions from the perspective of non-equilibrium thermodynamics. For first order quantum phase transitions, we find that the average work done per quench in crossing the critical point is discontinuous. This leads us to introduce the quantum latent work in analogy with the classical latent heat of first order classical phase transitions. For second order quantum phase transitions the irreversible work is closely related to the fidelity susceptibility for weak sudden quenches of the system Hamiltonian. We demonstrate our ideas with numerical simulations of first, second, and infinite order phase transitions in various spin chain models.Comment: accepted in PR

Mitochondrial roles of the psychiatric disease risk factor DISC1

Ion transport during neuronal signalling utilizes the majority of the brain's energy supply. Mitochondria are key sites for energy provision through ATP synthesis and play other important roles including calcium buffering. Thus, tightly regulated distribution and function of these organelles throughout the intricate architecture of the neuron is essential for normal synaptic communication. Therefore, delineating mechanisms coordinating mitochondrial transport and function is essential for understanding nervous system physiology and pathology. While aberrant mitochondrial transport and dynamics have long been associated with neurodegenerative disease, they have also more recently been linked to major mental illness including schizophrenia, autism and depression. However, the underlying mechanisms have yet to be elucidated, due to an incomplete understanding of the combinations of genetic and environmental factors contributing to these conditions. Consequently, the DISC1 gene has undergone intense study since its discovery at the site of a balanced chromosomal translocation, segregating with mental illness in a Scottish pedigree. The precise molecular functions of DISC1 remain elusive. Reported functions of DISC1 include regulation of intracellular signalling pathways, neuronal migration and dendritic development. Intriguingly, a role for DISC1 in mitochondrial homeostasis and transport is fast emerging. Therefore, a major function of DISC1 in regulating mitochondrial distribution, ATP synthesis and calcium buffering may be disrupted in psychiatric disease. In this review, we discuss the links between DISC1 and mitochondria, considering both trafficking of these organelles and their function, and how, via these processes, DISC1 may contribute to the regulation of neuronal behavior in normal and psychiatric disease states

Functional outcome of humeral shaft fractures in adults treated with titanium elastic nailing

Background: This study was done to analyse the functional outcome of humeral shaft fractures (upper and middle third) managed with closed ante-grade intramedullary titanium elastic nailing.Methods: This was a prospective study of 20 patients, aged between 18 and 60 years, with humeral shaft fractures treated with titanium elastic nailing from May 2016 to April 2018 at our institute. Upper and middle humeral shaft fractures of both sexes were included in the study.Results: Eighteen (90%) fractures united in 12-20 weeks. Two (10%) patients had delayed union which ultimately united without any intervention. Two (10%) patients developed shoulder stiffness due to nail impingement. By evaluating ASES score, good to excellent results were noted in 18 (90%) and moderate in 2 (10%). There were 15 males and 5 females with an average age 32.75 years (range: 18-60 years).Conclusions: Titanium elastic nailing is a good method for treatment of humeral shaft fractures in adults. It provides early fracture union, high union rates, minimal soft tissue damage, early rehabilitation and short hospital stay

Analysis of Tertiary Control for PV based Microgrid System

With the rising demand in electricity, increasing fuel cost, global climatic changes and concern on greenhouse gas emission the use of renewable energy resources is becoming a necessity. Microgrid is a systematic integration of various Distributed Energy Resources (DERs) and connected loads to operate as single entity which can either be connected to the grid or can operate as a separate independent island. Power electronic converters are employed to provide flexibility for the integration of various distributed energy sources in the grid. Microgrid draws power from utility grid or supplies to the grid depending upon load demand and generationin grid connected mode. In case of power interruption or load shedding microgrid can be switchedto island mode of operation. One of the important issues of microgrid is to achieve the bump less transition between the grid and islanded mode of operation. In this paper Photo voltaic (PV) sources based microgrid system has been considered and a coordinated control scheme for the control of a microgrid system is implemented in Matlab / Simulink environment. This paper investigates the bump less transition between the grid and islanded mode of operation with reduced harmonic distortion and frequency variation