187 research outputs found
Biomechanical aspects of the anterior segment in human myopia
The thesis investigates the relationship between the biomechanical properties of the anterior human sclera and cornea in vivo using Schiotz tonometry (ST), rebound tonometry (RBT, iCare) and the Ocular Response Analyser (ORA, Reichert). Significant differences in properties were found to occur between scleral quadrants. Structural correlates for the differences were examined using Partial Coherent Interferometry (IOLMaster, Zeiss), Optical Coherent tomography (Visante OCT), rotating Scheimpflug photography (Pentacam, Oculus) and 3-D Magnetic Resonance Imaging (MRI). Subject groups were employed that allowed investigation of variation pertaining to ethnicity and refractive error. One hundred thirty-five young adult subjects were drawn from three ethnic groups: British-White (BW), British-South-Asian (BSA) and Hong-Kong-Chinese (HKC) comprising non-myopes and myopes. Principal observations: ST demonstrated significant regional variation in scleral resistance a) with lowest levels at quadrant superior-temporal and highest at inferior-nasal; b) with distance from the limbus, anterior locations showing greater resistance. Variations in resistance using RBT were similar to those found with ST; however the predominantly myopic HKC group had a greater overall mean resistance when compared to the BW-BSA group. OCT-derived scleral thickness measurements indicated the sclera to be thinner superiorly than inferiorly. Thickness varied with distance from the corneolimbal junction, with a decline from 1 to 2 mm followed by a successive increase from 3 to 7 mm. ORA data varied with ethnicity and refractive status; whilst axial length (AL) was associated with corneal biometrics for BW-BSA individuals it was associated with IOP in the HKC individuals. Complex interrelationships were found between ORA Additional-Waveform-Parameters and biometric data provided by the Pentacam. OCT indicated ciliary muscle thickness to be greater in myopia and more directly linked to posterior ocular volume (from MRI) than AL. Temporal surface areas (SAs, from MRI) were significantly smaller than nasal SAs in myopic eyes; globe bulbosity (from MRI) was constant across quadrants
Investigation of multimolecular complexes and signalling in chronic myeloid leukaemia (CML).
Imperial Users onl
Case Study on Rejected Patents in India
India is a country that has understood the importance of strong patent systems for the growth of industry and commerce to bring it at par with the modern world. As per WIPO statistical database September 2018, 45,379 patent applications were filed in India. Out of which, 12,387 applications were granted and 29,789 applications were withdrawn or abandoned by the applicants. About 3203 patents were rejected on the ground of non-fulfillment of patentability criteria by the invention, that is, Novelty, non-obviousness and Industrial applicability or non-patentability criteria mentioned under Sections 3 and 4 of Indian Patent Act. In this chapter, the authors have discussed few of the cases of rejection under the Indian Patent Act
Decolonising the Curriculum Within a Block Teaching Structure: A Beginning
The murder of George Floyd in Minnesota on May 25th 2020 sparked Black Lives Matter protests across the globe. The protests focused on race and racism and highlighted structural inequalities that are faced by people racialized as Black. As a British South Asian woman, the murder of George Floyd had a profound effect on me both personally and professionally. As a lecturer within a UK Higher Education institution, although I was aware of the decolonising agenda and was involved in relevant initiatives, the momentum of the BLM protests sparked a long time coming urgent progression of this agenda from the periphery into the mainstream. This paper highlights the first steps in my journey towards decolonising my curriculum
Biomechanical aspects of the anterior segment in human myopia
The thesis investigates the relationship between the biomechanical properties of the anterior human sclera and cornea in vivo using Schiotz tonometry (ST), rebound tonometry (RBT, iCare) and the Ocular Response Analyser (ORA, Reichert). Significant differences in properties were found to occur between scleral quadrants. Structural correlates for the differences were examined using Partial Coherent Interferometry (IOLMaster, Zeiss), Optical Coherent tomography (Visante OCT), rotating Scheimpflug photography (Pentacam, Oculus) and 3-D Magnetic Resonance Imaging (MRI). Subject groups were employed that allowed investigation of variation pertaining to ethnicity and refractive error. One hundred thirty-five young adult subjects were drawn from three ethnic groups: British-White (BW), British-South-Asian (BSA) and Hong-Kong-Chinese (HKC) comprising non-myopes and myopes. Principal observations: ST demonstrated significant regional variation in scleral resistance a) with lowest levels at quadrant superior-temporal and highest at inferior-nasal; b) with distance from the limbus, anterior locations showing greater resistance. Variations in resistance using RBT were similar to those found with ST; however the predominantly myopic HKC group had a greater overall mean resistance when compared to the BW-BSA group. OCT-derived scleral thickness measurements indicated the sclera to be thinner superiorly than inferiorly. Thickness varied with distance from the corneolimbal junction, with a decline from 1 to 2 mm followed by a successive increase from 3 to 7 mm. ORA data varied with ethnicity and refractive status; whilst axial length (AL) was associated with corneal biometrics for BW-BSA individuals it was associated with IOP in the HKC individuals. Complex interrelationships were found between ORA Additional-Waveform-Parameters and biometric data provided by the Pentacam. OCT indicated ciliary muscle thickness to be greater in myopia and more directly linked to posterior ocular volume (from MRI) than AL. Temporal surface areas (SAs, from MRI) were significantly smaller than nasal SAs in myopic eyes; globe bulbosity (from MRI) was constant across quadrants.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Analysis of developmentally regulated cold tolerance in Arabidopsis thaliana and characterization of cold regulated sulfotransferases in Triticum aestivum
The large differences in freezing tolerance that exist between winter and spring wheat cultivars suggest that the regulation of the initiation of reproductive organs and development plays an important role in the potential of the plant to cold acclimate, which is a process of treating the plants at low non-freezing temperatures in order to increase its freezing tolerance ability. Because of the advantages of analyzing in model species, we have studied the changes in the capacity of Arabidopsis thaliana to cold acclimate at different stages of development. We have found that freezing tolerance decreases after flowering, with a critical and abrupt drop in the tolerance two days after the opening of the first flowers. Freezing tolerance was increased after flowering by the exogenous application of abscisic acid (ABA) and by sodium nitroprusside (SNP) which produces NO, thus implicating ABA and NO in the signaling pathways involved in cold acclimation. In addition, we have found that the expression of three wheat sulfotransferases (ST) namely: TaST2, TaST3 and TaST4 are regulated during cold acclimation. Molecular characterization of TaST2, TaST3 and TaST4 revealed that the deduced amino acid sequences of all three enzymes contained the conserved regions and amino acids involved in 3'-phosphoadenosine 5'-phosphosulfate (PAPS) binding and catalysis (Varin, 1992 and Marsolais, 1995). All three sulfotransferases were found to be differentially regulated by cold in winter and spring wheat. Wheat EST clone collections were used to sub-clone TaST2, TaST3 and TaST4 in a bacterial expression vector pQE30. The purified recombinant proteins were tested for purity by SDS-PAGE and various ranges of compounds were tested as possible substrate
PYRIMIDINE INCORPORATED SCHIFF BASE OF ISONIAZID WITH THEIR SYNTHESIS, CHARACTERIZATION AND IN VITRO BIOLOGICAL EVALUATION
  Objective: Versatile biological activities of nitrogen containing heterocycles in medicinal chemistry, mainly pyrimidine and pyridine ring based heterocyclic moieties are very important. Pharmaceutical important of pyrimidine and isoniazid moiety prompted us to synthesize isoniazid clubbed pyrimidine derivatives and evaluated for antimicrobial and antituberculosis activity.Method: 2-(2-(3-bromo benzylidene)-1-isonicotinoyl hydrazinyl)-N-(4-(substituted phenyl)-6-(substituted aryl) pyrimidin-2-yl) acetamide 2(A-J) have been synthesized by condensation reaction of 2-chloro-N-[4-(substituted phenyl)-6-(substituted aryl) pyrimidin-2-yl] acetamide and N'-[(E)- (3-bromophenyl) methylidene]pyridine-4-carbohydrazide. All newly synthesized compounds were screened for in vitro antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus pyogenes, antifungal against Candida albicans, Aspergillus niger, and Aspergillus clavatus, and antituberculosis activity against Mycobacterium tuberculosis H37RV.Results: Majority of the compounds exhibited good antibacterial, antifungal, and antituberculosis activity. All titled compounds were characterized by spectral analyses (infrared spectroscopy, nuclear magnetic resonance spectroscopy, and mass spectroscopy).Conclusion: 2-(2-(3-bromo benzylidene)-1-isonicotinoyl hydrazinyl)-N-(4-(substituted phenyl)-6-(substituted aryl) pyrimidin-2-yl) acetamide 2(A-J) showed good antimicrobial activity and comparatively good antituberculosis activity. Hence, all the compounds of this series considered for future investigation mainly in area of antibacterial, antifungal study
Investigating the effect of pupil seating arrangements on student discussion in a mathematics classroom
The main purpose of this action research study was to investigate the different types of verbal interactions by students in a mathematics classroom. The study used indicators to quantify different interactions using a voice recorder with one class of students in two different seating arrangements. The results shows students engaged in much more discussion when sat in groups compared with rows, however the proportion of mathematical discussion in rows was higher than in groups. The principal conclusion was the work required with students to ensure they could focus their discussion and how the teacher could facilitate this within lessons
PULSATILE RELEASE OF KETOPROFEN FROM COMPRESSION COATED TABLETS USING EUDRAGIT® POLYMERS
Objective: The objective of the present research work is to develop compression coated tablet of ketoprofen as a pulsatile release system for treatment of rheumatoid arthritis.Methods: Core tablets of ketoprofen were prepared using the wet granulation method and evaluated for appearance, hardness, friability, weight variation, thickness, disintegration time and % drug release. Core tablets were coated with Eudragit S100 and Eudragit L100 by compression coating method to achieve desired lag time. The blends of core and coating materials were evaluated for bulk density, tapped density, Hausner's ratio, % Compressibility index and angle of repose. Compression coated tablets were evaluated for appearance, hardness, friability, weight variation, thickness and % drug release.Results: Core tablets, as well as compression coated tablets, showed acceptable Pharmaco technical properties. Optimized core tablets were disintegrated within 15s due to the effectiveness of super disintegrant, sodium starch glycolate. Dissolution studies of compression coated tablets in media with different pH (1.2, 6.8, and 7.4) showed that drug release could be modulated by changing the concentration of EudragitL100 and Eudragit S100. The optimized batch exhibited 80% drug release up to 6 h with a 4 h lag time. Stability study of the optimized formulation indicated no significant change in appearance, physical parameters, drug content and drug release profile at accelerated conditions for two months.Conclusion: compression coated tablet of ketoprofen was successfully developed to achieve burst drug release after specific lag time.Keywords: Chronomodulated drug delivery, Pulsatile release, Compression coated tablets, Lag tim
Development and validation of dissolution method for carvedilol compression-coated tablets
The present study describes the development and validation of a dissolution method for carvedilol compression-coated tablets. Dissolution test was performed using a TDT-06T dissolution apparatus. Based on the physiological conditions of the body, 0.1N hydrochloric acid was used as dissolution medium and release was monitored for 2 hours to verify the immediate release pattern of the drug in acidic pH, followed by pH 6.8 in citric-phosphate buffer for 22 hours, to simulate a sustained release pattern in the intestine. Influences of rotation speed and surfactant concentration in medium were evaluated. Samples were analysed by validated UV visible spectrophotometric method at 286 nm. 1% sodium lauryl sulphate (SLS) was found to be optimum for improving carvedilol solubility in pH 6.8 citric-phosphate buffer. Analysis of variance showed no significant difference between the results obtained at 50 and 100 rpm. The discriminating dissolution method was successfully developed for carvedilol compression-coated tablets. The conditions that allowed dissolution determination were USP type I apparatus at 100 rpm, containing 1000 ml of 0.1N HCl for 2 hours, followed by pH 6.8 citric-phosphate buffer with 1% SLS for 22 hours at 37.0 ± 0.5 ºC. Samples were analysed by UV spectrophotometric method and validated as per ICH guidelines.O presente estudo descreve o desenvolvimento e a validação de método de dissolução para comprimidos revestidos de carvedilol. O teste de dissolução foi efetuado utilizando-se o aparelho para dissolução TDT-06T. Com base nas condições fisiológicas do organismo, utilizou-se ácido clorídrico 0,1 N como meio de dissolução e a liberação foi monitorada por 2 horas para se verificar o padrão de liberação imediata do fármaco em condições de pH baixo, seguidas por pH 6,8 em tampão cítrico-fosfato por 22 horas, para simular o padrão de liberação controlada no intestino. Avaliou-se a influência da velocidade de rotação e a concentração de tensoativo no meio. As amostras foram analisadas por método espectrofotométrico UV-visível validado, em 286 nm. O laurilsulfato sódico a 1% (SLS) mostrou-se ótimo para aumentar a solubilidade do carvedilol em pH 6,8 em tampão cítrico-fosfato. A análise da variância não mostrou diferença significativa entre os resultados obtidos a 50 e a 100 rpm. O método da dissolução discriminante foi desenvolvido com sucesso para os comprimidos revestidos de carvedilol. As condições que permitiram a determinação da dissolução foram: aparelho USP tipo I a 100 rpm, contendo 1000 mL de HCL 0,1 N por 2 horas, seguido de pH 6,8 com tampão cítrico-fosfato, com 1% de SLS por 22 horas a 37,0 ± 0,5 ºC. Amostras foram analisadas por método espectrofotométrico e validadas pelas normas ICH
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