Surface Crosslinked Gelatin Nanoparticles As New Tool for the Delivery of Hydrophilic Macromolecular Drugs

For the delivery of hydrophilic macromolecules, a novel flexible, hydrophilic delivery system based on gelatin nanoparticles is developed. Stabilization of gelatin in water is addressed using an apolar zero length crosslinker, i.e., diisopropylcarbodiimide (DIC). Crosslinking of GNPs with polar crosslinkers has certain limitations not only crosslinking gelatin nanoparticles but also the loaded proteins, which interfere not only in the release of cargo but also their biological activity. Therefore, we introduced a novel crosslinking approach termed as interfacial crosslinking with the application of DIC which specifically crosslink the colloidal interface and not diffusing into the interior of nanoparticle. In this context, critical process parameters involved in the crosslinking process have been investigated in order to obtain optimum preparation conditions. The main challenge while formulating these surface crosslinked gelatin nanoparticles (scGNPs) was purification. The centrifugation results in the formation of non redispersible pellet. Therefore, we optimized tangential flow filtration as a promising alternative purification tool. For the final proof of our hypothesis that the hydrophobic crosslinker crosslink only the colloidal interface of GNPs without crosslinking the loaded protein, the surface crosslinked GNPs were loaded with a model hydrophilic protein, i.e., lysozyme. This proved scGNPs as a flexible delivery system for protein based drugs

Structural topology optimisation based on the Boundary Element and Level Set methods

The research work presented in this thesis is related to the development of structural optimisation algorithms based on the boundary element and level set methods for two and three-dimensional linear elastic problems. In the initial implementation, a stress based evolutionary structural optimisation (ESO) approach has been used to add and remove material simultaneously for the solution of two-dimensional optimisation problems. The level set method (LSM) is used to provide an implicit description of the structural geometry, which is also capable of automatically handling topological changes, i.e. holes merging with each other or with the boundary. The classical level set based optimisation methods are dependent on initial designs with pre-existing holes. However, the proposed method automatically introduces internal cavities utilising a stress based hole insertion criteria, and thereby eliminates the use of initial designs with pre-existing holes. A detailed study has also been carried out to investigate the relationship between a stress and topological derivative based hole insertion criteria within a boundary element method (BEM) and LSM framework. The evolving structural geometry (i.e. the zero level set contours) is represented by non-uniform rational b-splines (NURBS), providing a smooth geometry throughout the optimisation process and completely eliminating jagged edges. The BEM and LSM are further combined with a shape sensitivity approach for the solution of minimum compliance problems in two-dimensions. The proposed sensitivity based method is capable of automatically inserting holes during the optimisation process using a topological derivative approach. In order to investigate the associated advantages and disadvantages of the evolutionary and sensitivity based optimisation methods a comparative study has also been carried out. There are two advantages associated with the use of LSM in three-dimensional topology optimisation. Firstly, the LSM may readily be applied to three-dimensional space, and it is shown how this can be linked to a 3D BEM solver. Secondly, the holes appear automatically through the intersection of two surfaces moving towards each other. Therefore, the use of LSM eliminates the need for an additional hole insertion mechanism as both shape and topology optimisation can be performed at the same time. A complete algorithm is proposed and tested for BEM and LSM based topology optimisation in three-dimensions. Optimal geometries compare well against those in the literature for a range of benchmark examples

Projection neurons in lamina III of the rat spinal cord are selectively innervated by local dynorphin-containing excitatory neurons

Large projection neurons in lamina III of the rat spinal cord that express the neurokinin 1 receptor are densely innervated by peptidergic primary afferent nociceptors and more sparsely by low-threshold myelinated afferents. However, we know little about their input from other glutamatergic neurons. Here we show that these cells receive numerous contacts from nonprimary boutons that express the vesicular glutamate transporter 2 (VGLUT2), and form asymmetrical synapses on their dendrites and cell bodies. These synapses are significantly smaller than those formed by peptidergic afferents, but provide a substantial proportion of the glutamatergic synapses that the cells receive (over a third of those in laminae I–II and half of those in deeper laminae). Surprisingly, although the dynorphin precursor preprodynorphin (PPD) was only present in 4–7% of VGLUT2 boutons in laminae I–IV, it was found in 58% of the VGLUT2 boutons that contacted these cells. This indicates a highly selective targeting of the lamina III projection cells by glutamatergic neurons that express PPD, and these are likely to correspond to local neurons (interneurons and possibly projection cells). Since many PPD-expressing dorsal horn neurons respond to noxious stimulation, this suggests that the lamina III projection cells receive powerful monosynaptic and polysynaptic nociceptive input. Excitatory interneurons in the dorsal horn have been shown to possess IA currents, which limit their excitability and can underlie a form of activity-dependent intrinsic plasticity. It is therefore likely that polysynaptic inputs to the lamina III projection neurons are recruited during the development of chronic pain states

APPLICATION OF KEITH MORROW`S FEATURES OF COMMUNICATIVE LANGUAGE TESTING TO A TEST OF “COMMUNICATION SKILLS” AT MBA LEVEL

Since the 1970s, an innovative theory regarding language and language use exerted a noticeable effect on language teaching and language testing. Testing is essential in the learning process and is acrucial aspect of teaching. But language testing has traditionally been taken the form of testing knowledge about language , usually the testing of knowledge of vocabulary and grammar . However , language testing is much more than simple testing of vocabulary and grammar. So, communicative language tests are designed to measure the ability of the testees to use target language in real life situations. However , language testing in Pakistan in not based on Communicative Language Testing approach. The present research evaluates a test of ‘ Communication skills ’ module taught at MBA (Master of Business Administration) level (Appendix-A) . Keith Morrow’ s (1979) Seven Features of Communication, based on Holistic approach to language testing, has been used as criterion to evaluate the appropriateness of the above mentioned test. A revised test of reading and speaking skills in the light of Morrow’ s features has been proposed in the end (Appe ndix-B)

Spinal cord neuronal circuitry involving dorsal horn projection cells

The spinal cord dorsal horn is involved in the processing and transmission of sensory information to the brain. There are several distinct populations of dorsal horn projection cells that constitute the major output of the spinal cord. These cells are mostly found in lamina I and are scattered throughout the deep dorsal horn. There is a population of large lamina III projection cells that expresses the neurokinin 1 receptor (NK1r), which is the main target for substance P released by nociceptive primary afferents. These cells are densely innervated by peptidergic nociceptive afferents and more sparsely by low-threshold myelinated afferents. In addition, they also receive selective innervation from neuropeptide Y-containing inhibitory interneurons. However, not much is known about their input from glutamatergic spinal neurons. It has already been reported that the great majority of large lamina III NK1r expressing cells project to caudal ventrolateral medulla (CVLM) therefore in this study these cells were easily identified without retrograde tracer injection. Preliminary observations showed that these cells received contacts from preprodynorphin (PPD)-containing excitatory axons. The first part of the study tested the hypothesis that lamina III projection cells are selectively targeted by PPD-containing excitatory spinal neurons. Spinal cord sections from lumbar segments of the rat underwent immunocytochemical processing including combined confocal and electron microscopy to look for the presence of synapses at the sites of contact. The results showed that lamina III NK1r cells received numerous contacts from non-primary boutons that expressed vesicular glutamate transporter 2 (VGLUT2), and formed asymmetrical synapses on their dendrites and cell bodies. These synapses were significantly smaller than those formed by peptidergic afferents but provided a substantial proportion of the glutamatergic input to lamina III NK1r projection cells. Furthermore, it was observed that PPD was found to be present in ~58% of the VGLUT2 boutons that contacted these cells while a considerably smaller proportion of (5-7%) VGLUT2 boutons in laminae I-IV expressed PPD. These results indicate a highly selective targeting of the lamina III projection neurons by glutamatergic neurons that express PPD. Fine myelinated (Aδ) nociceptors are responsible for the perception of fast, well-localised pain. Very little is known about their postsynaptic targets in the spinal cord, and therefore about their roles in the neuronal circuits that process nociceptive information. In the second part of the study, Fluorogold injections were made into the lateral parabrachial region (LPb) of the rat brain on one side and cholera toxin B subunit (CTb) was injected into the sciatic nerve on the contralateral side to assess whether Aδ nociceptors provide input to lamina I projection cells. The vast majority of lamina I projection neurons belong to the spinoparabrachial tract, and these can be divided into two major groups: those that express NK1r, and those that do not. The results suggested that CTb labelled a distinct set of Aδ nociceptors, most of which lack neuropeptides. CTb-labelled Aδ afferents formed contacts on 43% of the spinoparabrachial lamina I neurons that lacked the NK1r, but on a significantly smaller proportion (26%) of NK1r projection cells. Combined confocal and electron microscopy established that the contacts were associated with synapses. Furthermore, the contact density of CTb labelled boutons was considerably higher on the NK1r- cells than on those with the NK1r. These results provide further evidence that primary afferents input to projection cells is organized in a specialized way and that both NK1r+ and NK1r- lamina I projection neurons are directly innervated by Aδ nociceptors, thus may have an important role in the perception of fast pain. Lamina I of the rat spinal cord dorsal horn contains a population of large spinoparabrachial projection neurons (giant cells) that receive numerous synapses from both excitatory (VGLUT2) and inhibitory (VGAT) interneurons. The giant cells are selectively innervated by GABAergic axons that express neuronal-nitric oxide synthase (nNOS) and are thought to originate from local inhibitory interneurons. In the rat, the nNOS inhibitory cells belong to a distinct functional population that differs from other inhibitory interneurons in terms of somatostatin receptor (sst2A) expression and also in responsiveness to painful stimuli. There is a population of inhibitory interneurons that express green fluorescent protein (GFP) in lamina II of mice in which GFP is under control of the prion promoter (PrP) and the great majority of these cells also express nNOS. In this part of the study, the inhibitory synaptic input from nNOS-containing GFP boutons to giant lamina I cells was investigated. The great majority of lamina I projection neurons express NK1 receptor; therefore, the possibility that lamina I NK1r-expressing projection neurons received innervation from GFP+/nNOS+ axons was also tested. Since retrograde tracing technique was not used in this part of the study, lamina I projection cells were identified based on the observations made in the previous studies in the rat. Lamina I giant cells were recognized with antibodies against glycine receptor associated protein gephyrin as well as VGLUT2 and VGAT boutons, all of which provide dense innervation to these cells while only those lamina I NK1cells were included in the sample that were large and strongly immunoreactive for NK1r. The results indicated that although GFP axons accounted for only 7-9% of the GABAergic boutons in superficial dorsal horn, they provided over 70% of the inhibitory synapses on most of the giant cells in the PrP-GFP mouse and the great majority of these boutons also contained nNOS. Moreover, a subset of large lamina I NK1r-expressing cells (18/60) received a substantial inhibitory input (> 30%) from GFP+ boutons while the majority of these neurons showed sparse (< 15%) synaptic input. Recently, it has been reported that loss of some inhibitory interneurons in mice lacking the transcription factor Bhlhb5 results in exaggerated itch, and the cells that are lost include many of those that would normally express nNOS. Therefore, in the final set of experiments was designed to test whether there is a reduction in the inhibitory synaptic input to the giant cells in Bhlhb5-/- mouse. Spinal cord sections from Bhlhb5-/- mice and the wild type littermates were processed and analysed to determine any difference in the inhibitory nNOS input to lamina I giant cells belonging to either group. The giant cells from the knockout mice showed a substantial reduction (~80%) in their inhibitory nNOS input; with a moderate reduction in their overall GABAergic input (~35%). There was a considerable increase in nNOS-/VGAT+ boutons in the Bhlhb5-/- mouse (18 ± 4.6 and 37.7 ± 8.2/100 µm of the dendrite in WT and KO, respectively), suggesting some compensation from other nNOS-negative inhibitory interneurons. These results suggest that the loss of nNOS-containing inhibitory synaptic input to lamina I projection cells may contribute to the abnormal scratching behaviour seen in the Bhlhb5-/- mouse. This raises the possibility that the giant cells and a subset of large lamina I NK1r-expressing cells are involved in perception of itch

Research Aptitudes Among University Teachers and Impacts on Instructional Quality: A Review Paper

Generating new practices and ideas are the key principles of higher education instructions. For teaching at university level research aptitude, innovative competence and knowledge are becoming increasingly important in today’s education. In comparison to other professionals’ teachers are required to enhance their aptitude toward research and innovative practices more. Teacher who is engaged in research at his/her professional practice, contributes much to his education career and keep his / her field up to date. A strong research aptitude of university teachers makes a teacher strong, innovative and productive in his/her teaching profession. The present paper offers reviews of articles and previous studies about aptitude of teachers toward research and the impact on their teaching practices. The review points to the vital importance of research engagement in teaching career. Thus, the investigator argues that there is a greater need of aptitude toward research for teachers who teach at university level.&nbsp