Adsorption and binding dynamics of graphene-supported phospholipid membranes using the QCM-D technique

We report on the adsorption dynamics of phospholipid membranes on graphene-coated substrates using the quartz crystal microbalance with dissipation monitoring (QCM-D) technique. We compare the lipid vescle interaction and membranne formation on gold and silicon dioxide QCM crystal surfaces with their graphene oxide (GO) and reduced (r)GO coated counterparts, and report on the different lipid structures obtained. We establish graphene derivative coatings as support surfaces with tuneable hydrophobicity for the formation of controllable lipid structures. One structure of interest formed are lipid monolayer membrannes which were formed on rGO, which are otherwise challenging to produce. We also demonstrate and monitor biotin-avidin binding on such a membranne, which will then serve as a platform for a wide range of biosensing applications. The QCM-D technique could be extended to both fundamental studies and applications of other covalent and non-covalent interactions in 2-dimensional materials

Position determination of a lander and rover at Mars with Earth-based differential tracking

The presence of two or more landed or orbiting spacecraft at a planet provides the opportunity to perform extremely accurate Earth-based navigation by simultaneously acquiring Doppler data and either Same-Beam Interferometry (SBI) or ranging data. Covariance analyses were performed to investigate the accuracy with which lander and rover positions on the surface of Mars can be determined. Simultaneous acquisition of Doppler and ranging data from a lander and rover over two or more days enables determination of all components of their relative position to under 20 m. Acquiring one hour of Doppler and SBI enables three dimensional lander-rover relative position determination to better than 5 m. Twelve hours of Doppler and either SBI or ranging from a lander and a low circular or half synchronous circular Mars orbiter makes possible lander absolute position determination to tens of meters

Are Granulins Copper Sequestering Proteins?

Granulins (GRN 1-7) are short (~6 kDa), cysteine-rich proteins that are generated upon the proteolytic processing of progranulin (PGRN). These peptides, along with their precursor, have been implicated in multiple pathophysiological roles, especially in neurodegenerative diseases. Previously we showed that GRN-3 and GRN-5 are fully disordered in the reduced form implicating redox sensitive attributes to the proteins. Redox-based modulations are often carried out by metalloproteins in mitigating oxidative stress and maintaining metal-homeostasis within cells. To probe whether GRNs play a role in metal sequestration, we tested the metal binding propensity of the reduced forms of GRNs −3 and − 5 under neutral and acidic pH mimicking cytosolic and lysosomal conditions, respectively. We found, at neutral pH, both GRNs selectively bind Cu and no other divalent metal cations, with a greater specificity for Cu(I). Binding of Cu did not result in a disorder-to-order structural transition but partly triggered the multimerization of GRNs via uncoordinated cystines at both pH conditions. Overall, the results indicate that GRNs −3 and − 5 have surprisingly strong affinity for Cu in the pM range, comparable to other known copper sequestering proteins. The results also hint at a potential of GRNs to reduce Cu(II) to Cu(I), a process that has significance in mitigating Cu-induced ROS cytotoxicity in cells. Together, this report uncovers metal-coordinating property of GRNs for the first time, which may have profound significance in their structure and pathophysiological functions

Entanglement transitions in random definite particle states

Entanglement within qubits are studied for the subspace of definite particle states or definite number of up spins. A transition from an algebraic decay of entanglement within two qubits with the total number $N$ of qubits, to an exponential one when the number of particles is increased from two to three is studied in detail. In particular the probability that the concurrence is non-zero is calculated using statistical methods and shown to agree with numerical simulations. Further entanglement within a block of $m$ qubits is studied using the log-negativity measure which indicates that a transition from algebraic to exponential decay occurs when the number of particles exceeds $m$. Several algebraic exponents for the decay of the log-negativity are analytically calculated. The transition is shown to be possibly connected with the changes in the density of states of the reduced density matrix, which has a divergence at the zero eigenvalue when the entanglement decays algebraically.Comment: Substantially added content (now 24 pages, 5 figures) with a discussion of the possible mechanism for the transition. One additional author in this version that is accepted for publication in Phys. Rev.

Formulation and Invitroevaluation of Levofloxacin Loaded Floating Microsphere

This thesis deals with the investigation carried out on the formulation and evaluation of Levofloxacin loaded loaded floating microsphere so as to improve its gastric residence time, to decrease dosing frequency, maintain prolonged therapeutic levels of the drug following dosing and to reduce the dose to achieve same pharmacological effect. Based on the literature studies various excipients HPMC K4M, sodium alginate, sodium CMC, HPMC K100M, Methanol, Dichloromethane were selected for the preparation of floating microspheres. In preformulation studies, compatibility of the selected polymers and levofloxacin were carried by FT-IR peak matching method and results indicated no interaction between drug and excipients. Floating microspheres were prepared by solvent evaporation method and the effect of certain polymers and formulation was studied. The study on various polymers revealed that all the polymers are important in formulation of floating microspheres. F7 prepared showed maximum release and was selected as ideal batch. Levofloxacin floating microsphere were evaluated formicromeritics properties, entrapment efficiency, Buoyancy studies, in-vitro release studies and kinetics of drug release. In order to elucidate mode and mechanism of drug release the in-vitro data was transformed and interpreted at graphical interface constructed using kinetic models. The mechanism of drug release from microspheres follows Non-Fickian release. It was concluded that solvent evaporation method was suitable for producing floating microsphere Levofloxacin hemihydrate was successfully incorporated into the microspheres using selective polymers. Floating microsphere provided sustained release of the drug. It was concluded that levofloxacin hemihydrate floating microspheres was prepared successfully with increased gastric residence time for better delivery of antibioticsfor improved therapy

AflaB2® and osteoarthritis: a multicentric, observational, post-marketing surveillance study in Indian patients suffering from knee osteoarthritis

Background: Osteoarthritis (OA) is one of the most debilitating chronic degenerative joint disorder characterized by pain, inflammation and stiffness of joints with wear and tear of the cartilage. Recent evidences suggest the involvement of the immune pathway in OA development. This study was conducted to evaluate the efficacy and safety of AflaB2® capsules containing Aflapin® and native collagen type II in knee OA patients.Methods: Total 40 knee OA subjects were enrolled at the out-patient department (OPD) of three different sites under supervision of physicians as per the inclusion and exclusion criteria of the study. Subjects were instructed to consume AflaB2® capsules once daily orally for three months. They were informed to visit the respective study center as per the schedule visits to assess and record the efficacy and safety.Results: AflaB2® treatment showed significant reduction in pain and stiffness with improvement in physical functions compared to the baseline. The reduction in pain score was observed from 2nd visit on visual analogue scale (VAS). The VAS score was reduced to 1.63±1.23 (p<0.001) from its baseline score 6.0±1.04 at the end of the treatment. The WOMAC Total Score was reduced to 18.1±6.04 (p<0.001) from its baseline score 74.4±8.07 at the end of the treatment. The improvement was observed in WOMAC pain, stiffness and physical functions score. No significant side-effect was reported with AflaB2® treatment throughout the study.Conclusions: The present study provides the evidence in support of the potential efficacy and excellent tolerability of oral intake of AflaB2® capsules in reducing OA symptoms

Purification and Biochemical Characterisation of Ricin from Castor Seeds

Ricin is a highly toxic plant toxin of Ricinus comtnunis seeds, commonly known as castor seeds. The toxin was extracted and purified using affinity and size exclusion  chromatography. The purity of ricin was evaluated by the sodium dodecylsulphate-polyacrylamide gel electrophoresis. Purified ricin gives a single band under non-reduced condition and two bands under reduced condition. The molecular weight of ricin was 65,0000 approx. The subunit structure of ricin on treatment with p-mercaptoethanol (1 %) at molecular level revealed that the reducing agent converts ricin into two peptides. The molecular weight of these two peptides was estimated to be 34000 and 32000. The western-blot analysis revealed two dots for its two peptides in 29 kDa to 36 kDa regions. The heamagglutination litres for ricin and Ricinus communis agglutinins were 1:8 and 1:256. The purity of purified ricin was further confirmed by the electrophoresis and the western-blot analysis. The Indian variety of castor seeds, known as Ricinus communis used in this study, contains approx. 0.12 per cent ricin