11 research outputs found
Ophthalmology training in India during COVID-19 pandemic: Perspective from a tertiary eye care hospital
FORMULATION AND EVALUATION OF FLOATING MATRIX TABLETS OF TAPENTADOL HCL
The objective of the present study is to evaluate HPMC K100M, HPMC K15M and carbopol 934P as matrix formers in this design of floating tablets of tapentadol, a poorly water soluble drug. Floating tablet s of tapentadol (100 mg) were formulated employing (i) HPMC K100M (ii) HPMC K15M and (iii) Carbopol 934P as matrix formers at 30% and 50% strength, sodium bicarbonate at 7.5%, 10% & 12.5% strength as gas generating agent and the tablets were evaluated for floating and drug releases characteristics. Tapentadol floating tablets formulated employing HPMC K100M and HPMC K15M as matrix formers at 50% strength and containing sodium bicarbonate (12.5%) as gas generating agent exhibited floating over 36 to 48 h with a floating lag time of less than 1 min. These floating tablets also gave slow and controlled release of tapentadol over 24 h and were found suitable for once a day administration (24 h). HPMC K100M and HPMC K15M were better suitable as matrix formers than Carbopol 934P for floating tablets of tapentadol, a poorly water soluble drug. Key Words: Floating tablets, tapentadol Hydrochloride, HPMC K100M, Carbopol, and zero order releas
Synthesis of Polyurethane Based Hole-Transporting Materials and Application for Organic Light Emitting Diode
有機發光二極體將於下一個顯示器世代佔有一席之地,所以藉由不斷的材料改進與製程進步來提升此種顯示器的效率發光亮度以及壽命。本論文主要致力於合成良好的電洞注入及傳輸材料以提升發光元件的效能以及性質,並將此系列的電洞傳輸材料分子運用在有機電激發光元件中,試驗其作為電洞注入層及電洞傳輸層的性質並加以探討。且藉由不同製程方法提升元件表現 (1) 將所合成出的電洞傳輸單體利用表面修飾製程於玻璃基板上形成薄膜電洞傳輸層、(2) 利用真空蒸鍍的製程將所合成出的電洞傳輸層材料於共蒸鍍條件下形成電洞傳輸層以提升元件亮度、並利用共蒸鍍方法做為磷光與螢光發光材主體 (3) 藉由旋轉塗佈法均勻的修飾玻璃基板,將合成出的高分子材料是具有電洞傳輸性質的具羥基之卡唑衍生物和三苯基胺衍生物依不同比例以二異氰酸酯連接成聚氨酯型態,與以具羥基之卡唑衍生物以及具有電洞阻擋性質和電子傳輸性質的噁唑衍生物依不同比例以二異氰酸酯連接成聚氨酯型態共聚合物形成電洞傳輸層。聚氨酯本身結構即具有良好的電洞傳輸效果並於電激發光元件中,讓元件發光效率及亮度有效提升。There are many kinds of pathway to improve the OLED or PLED device performance. In this thesis, hole-transporting materials were been focused subject and different routes were also been provided, including using surface modified method technology to do the modification on ITO glass surface by using oligo (phenylene vilyene) silane as hole transporting layer in chapter 2, synthesized the 9-(4-pentaphenylphenylphenyl)-9H-carbazole and co-evaporated with α-NPB function as hole transporting material and host in chapter 3 and functionalized Polyurethanes containing carbazole, OXD and Triphenylamine-derived for hole-transporting material in OLED device in chapter 4, 5. New polymers and organic materials were used as the hole transport layer (HTL) to improve the device performance. Such materials are not only reduced the driving voltage but also improve the current efficiency. We also observed that the current efficiency in the device is increased due to more carrier injection and better electron-hole balance.摘要...…………………….....…………………………………………………….…2bstract…...……………………………………………………………………..…..3hapter 1 Introduction of Organic Light Emitting Diode-1 Classification of Organic Light Emitting Device………………………….…..11-2 Principles of Organic electroluminescence and OLED device structure….…..12-3 Energy Transfer Mechanism in PLED……………………….………………..25-4 Hole-transporting and Injecting Materials……..……………. ...…………..…29-5 Reference of introduction…………………………………....………………..34hapter 2odification on ITO Glass Surface by Using Oligo (phenylene vinylene)silane as Hole Transporting Layer in Organic Light Emitting Diode Devices-1 Introduction……………………………………………………………….……38-2 Experimental part………………………………………………………...….…41-3 Results and discussion…………………………………………………….……46-4 Conclusion……………………………………………………………….……..56-5 Reference………………………………………………………………….……57hapter 3ynthesis of 9-(4-pentaphenylphenylphenyl)-9H-carbazole for Hole-Transporting Material and Host in OLED Device-1 Introduction……………………………………………………………….……61-2 Experimental…………………………………………………………………...63-3 Results and discussion …………………………...……………………………67-4 Conclusion……………………………………………………….…………….84-5 Reference………………………………………………………………………84hapter 4arbazole Containing Polyurethanes as Hole-Transport Layer for Organic Light Emitting Diodes-1 Introduction……………………………………………………………….……87-2 Results and discussion…………………………………………………….……91-3 Conclusion……………………………………………………………………..116-4 Experimental Section…………………………………………………………..116-5 Reference………………………………………………………………………124hapter 5ontaining Triphenylamine-Derived Polyurethanes as Hole-Transporting Layers Exhibit High Current Efficiencies in PLED Devices-1 Introduction……………………………………………………………………130-2 Results and Discussion ..………………………………………………………133-3 Conclusion……………………………………………………………………..149-4 Experimental Section .…………………………………………………………149-4 Reference …..…………………………………………………………….…….158hapter 6unable Color Devices of Fluorene-Based Polymers for Light Emitting Diodes-1 Introduction………………………………………………………………..…...161-2 Experimental Section……………………………………………………..……163-3 Results and Discussion…………………………………………………..……..172-4 Conclusion………………………………………………………………..…….188-5 Reference…………………………………………………………………..…...189ppendix ………………………………………………………………………..…19
Synthesis, Docking and Anti-Tumor Activity of \beta-L-1,3-Thiazolidine Pyrimidine Nucleoside Analogues
In the search for effective, selective, and nontoxic antiviral and antitumor agents, a variety of strategies have been devised to design nucleoside analogues. Here we have described the versatile synthesis of β-L-1,3-thiazolidine nucleoside analogues. These analogues are all derived from the key stereochemically defined intermediate N-tert-butoxy-carbonyl-4-hydroxymethyl-1,3-thiazolidine-2-ol which was accessible in 57% yield starting from L-Cysteine methylester hydrochloride. N-tert-butoxycarbonyl-2-acyloxy-4-trityloxymethyl-1,3-thiazolidine was coupled with the pyrimidine bases in the presence of Lewis acids stannic chloride or trimethyl silyl triflate following Vorbruggen procedure. Proof of the structure and configuration was obtained through NMR, NMR, Mass, elemental analysis and NOE experiments. Docking and antitumor activity of these nucleoside analogues are also reported
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Accuracy of autorefraction in an adult Indian population.
PurposeAutorefractors allow non-specialists to quickly assess refractive error, and thus could be a useful component of large-scale vision screening programs. In order to better characterize the role of autorefraction for public health outreach programs in resource-limited settings, the diagnostic accuracy of two autorefractors was assessed relative to subjective refraction in an adult Indian population.MethodsAn optometrist refracted a series of patients aged ≥50 years at an eye clinic in Bangalore, India using the Nidek ARK-900 autorefractor first, followed by the 3nethra Royal autorefractor, and then subjective refraction. The diagnostic accuracy of each autorefractor for myopia, hyperopia, and astigmatism was assessed using subjective refraction as the reference standard, and measures of agreement between refractions were calculated.ResultsA total of 197 eyes in 104 individuals (mean age 63 ± 8 years, 52% female) were evaluated. Both autorefractors produced spherical equivalent estimates that were on average more hyperopic than subjective refraction, with a measurement bias of +0.16 D (95%CI +0.09 to +0.23D) for Nidek and +0.42 D (95%CI +0.28 to +0.54D) for 3nethra. When comparing pairs of measurements from autorefraction and subjective refraction, the limits of agreement were approximately ±1D for the Nidek autorefractor and ±1.75D for the 3Nethra autorefractor. The sensitivity and specificity of detecting ≥1 diopter of myopia were 94.6% (95%CI 86.8-100%) and 92.5% (95%CI 88.9-97.5%) for the Nidek, and 89.2% (95%CI 66.7-97.4) and 77.5% (95%CI 71.2-99.4%) for the 3Nethra. The accuracy of each autorefractor increased at greater levels of refractive error.ConclusionsThe sensitivity and specificity of the Nidek autorefractor for diagnosing refractive error among adults ≥50 years in an urban Indian clinic was sufficient for screening for visually significant refractive errors, although the relatively wide limits of agreement suggest that subjective refinement of the eyeglasses prescription would still be necessary
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Diagnostic accuracy of an iPad application for detection of visual field defects.
BACKGROUND/OBJECTIVES: Tablet-based perimetry could be used to test for glaucomatous visual field defects in settings without easy access to perimeters, although few studies have assessed diagnostic accuracy of tablet-based tests. The goal of this study was to determine the diagnostic accuracy of iPad perimetry using the visualFields Easy application. SUBJECTS/METHODS: This was a prospective, cross-sectional study of patients undergoing their first Humphrey Field Analyser (HFA) visual field test at a glaucoma clinic in India. Participants underwent 24-2 SITA Standard HFA testing and iPad-based perimetry with the visualFields Easy application. Reference standards for both visual field loss and suspected glaucoma were determined by ophthalmologist review of HFA results and optic disc photographs. Receiver operating characteristic curves were constructed to assess diagnostic accuracy at various test thresholds. RESULTS: 203 eyes from 115 participants were included, with 82 eyes classified as moderate or worse glaucoma. iPad perimetry had an area under the receiver operating characteristic (AUROC) curve of 0.64 (95% CI 0.57 to 0.71) for detection of any visual field defect relative to HFA and an AUROC of 0.68 (0.59 to 0.76) for detection of moderate or worse glaucoma relative to ophthalmologist examination. At a set specificity of 90%, the sensitivity of iPad perimetry for detection of moderate or worse glaucoma was 35% (22-48%). CONCLUSIONS: iPad perimetry using the visualFields Easy application had inadequate diagnostic accuracy to be used as a screening tool for glaucoma in this South Indian population