INVESTIGATING THE POTENTIAL OF AN ANTIDEPRESSANT INTRANASAL MUCOADHESIVE MICROEMULSION

Objective: The main aim of this study was to formulate, develop and optimized a duloxetine hydrochloride (dlx-hcl) loaded mucoadhesive microemulsion intended for intranasal administration.Methods: Established on solubility studies capmul mcm, transcutol-p, labrasol were used as oil, co-surfactant and surfactant respectively. The optimized mucoadhesive microemulsion prepared using water titration method was further characterized for particle size, polydispersity index, zeta potential and conductivity measurements followed by drug content, nasal cilio toxicity and biochemical estimation of the selected formulation.Results: All physicochemical parameters conducted, proved that dlx-hcl microemulsion was appropriate for nasal delivery. Chitosan, used as mucoadhesive polymer demonstrated enhanced retention time of the microemulsion in nasal mucosa with no signs of toxicity and epithelial damage. The particle size and zeta potential were found to be of 200 nm and-15 mV respectively considering the formulation safe for nasal delivery.Conclusion: This formulation strategy can be used as an effective targeting technique for the drugs having low bioavailability and poor brain penetration along with an effective method for the treatment long-term disease like depression

Achieving higher photoabsorption than group III-V semiconductors in silicon using photon-trapping surface structures

The photosensitivity of silicon is inherently very low in the visible electromagnetic spectrum, and it drops rapidly beyond 800 nm in near-infrared wavelengths. Herein, we have experimentally demonstrated a technique utilizing photon-trapping surface structures to show a prodigious improvement of photoabsorption in one-micrometer-thin silicon, surpassing the inherent absorption efficiency of gallium arsenide for a broad spectrum. The photon-trapping structures allow the bending of normally incident light by almost ninety degrees to transform into laterally propagating modes along the silicon plane. Consequently, the propagation length of light increases, contributing to more than an order of magnitude improvement in absorption efficiency in photodetectors. This high absorption phenomenon is explained by FDTD analysis, where we show an enhanced photon density of states while substantially reducing the optical group velocity of light compared to silicon without photon-trapping structures, leading to significantly enhanced light-matter interactions. Our simulations also predict an enhanced absorption efficiency of photodetectors designed using 30 and 100-nanometer silicon thin films that are compatible with CMOS electronics. Despite a very thin absorption layer, such photon-trapping structures can enable high-efficiency and high-speed photodetectors needed in ultra-fast computer networks, data communication, and imaging systems with the potential to revolutionize on-chip logic and optoelectronic integration.Comment: 24 pages, 4 figure

Chaotic behavior of ion exchange phenomena in polymer gel electrolytes through irradiated polymeric membrane

A desktop experiment has been done to show the nonlinearity in the I-V characteristics of an ion conducting electrochemical micro-system. Its chaotic dynamics is being reported for the first time which has been captured by an electronic circuit. Polyvinylidene fluoride-co-hexafluoropropene (PVdF-HFP) gel electrolyte comprising of a combination of plasticizers (ethylene carbonate and propylene carbonate) and salts have been prepared to study the exchange of ions through porous poly ethylene terephthalate (PET) membranes. The nonlinearity of this system is due to the ion exchange of the polymer gel electrolytes (PGEs) through a porous membrane. The different regimes of spiking and non-spiking chaotic motions are being presented. The possible applications are highlighted.Comment: To be appeared in Phys. Lett.

Role of dye structure in improved dyeing of cotton with direct dyes in presence of a redox system and influence of glucose in improving direct dye uptake on cotton

59-64<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" calibri;mso-fareast-theme-font:minor-latin;mso-hansi-theme-font:minor-latin;="" mso-bidi-font-family:"times="" new="" roman";mso-ansi-language:en-us;mso-fareast-language:="" en-us;mso-bidi-language:ar-sa"="">The dyeing of a cotton fabric with direct dye in presence and absence of a redox system (potassium persulphate/ammonium persulphate as oxidant and glucose as reducing agent) as well as in presence of a reducing agent (glucose) alone has been investigated. The dyeing properties studied are dye exhaustion, colour strength and wash fastness. The results of the study indicate that improvement is dye dependent and varies with the chromophore of the dye, irrespective of the auxochrome groups. When a redox system is used, the dyeing process proceeds via a free radical mechanism and a covalent bond is formed by the reaction of dye free radical and cellulose free radical. The increased life of free radical (dye or cellulose), due to stabilization by resonance, results in increased probability of reaction and thus improvement in dyeing properties. Improvement is also observed when glucose alone is used since glucose increases the accessible regions of the fibre to dyes. The probability of dye absorption thus increases due to the interaction of dispersive forces and, to some extent, H-bonding with the cellulose substrate. The use of glucose for after treatment to improve the dye fixation is time-saving as well as economical. </span

Unique Hyperspectral Response Design Enabled by Periodic Surface Textures in Photodiodes

The applications of hyperspectral imaging across disciplines such as healthcare, automobiles, forensics, and astronomy are constrained by the requirement for intricate filters and dispersion lenses. By utilization of devices with engineered spectral responses and advanced signal processing techniques, the spectral imaging process can be made more approachable across various fields. We propose a spectral response design method employing photon-trapping surface textures (PTSTs), which eliminates the necessity for external diffraction optics and facilitates system miniaturization. We have developed an analytical model to calculate electromagnetic wave coupling using the effective refractive index of silicon in the presence of PTST. We have extensively validated the model against simulations and experimental data, ensuring the accuracy of our predictions. We observe a strong linear relationship between the peak coupling wavelength and the PTST period along with a moderate proportional relation to the PTST diameters. Additionally, we identify a significant correlation between inter-PTST spacing and wave propagation modes. The experimental validation of the model is conducted using PTST-equipped photodiodes fabricated through complementary metal-oxide-semiconductor-compatible processes. Further, we demonstrate the electrical and optical performance of these PTST-equipped photodiodes to show high speed (response time: 27 ps), high gain (multiplication gain, M: 90), and a low operating voltage (breakdown voltage: ∼ 8.0 V). Last, we utilize the distinctive response of the fabricated PTST-equipped photodiode to simulate hyperspectral imaging, providing a proof of principle. These findings are crucial for the progression of on-chip integration of high-performance spectrometers, guaranteeing real-time data manipulation, and cost-effective production of hyperspectral imaging systems

Design and Fabrication of High-Efficiency, Low-Power, and Low-Leakage Si-Avalanche Photodiodes for Low-Light Sensing.

Since the advent of impact ionization and its application in avalanche photodiodes (APD), numerous application goals have contributed to steady improvements over several decades. The characteristic high operating voltages and the need for thick absorber layers (π-layers) in the Si-APDs pose complicated design and operational challenges in complementary metal oxide semiconductor integration of APDs. In this work, we have designed a sub-10 V operable Si-APD and epitaxially grown the stack on a semiconductor-on-insulator substrate with a submicron thin π-layer, and we fabricated the devices with integrated photon-trapping microholes (PTMH) to enhance photon absorption. The fabricated APDs show a substantially low prebreakdown leakage current density of ∼50 nA/mm2. The devices exhibit a consistent ∼8.0 V breakdown voltage with a multiplication gain of 296.2 under 850 nm illumination wavelength. We report a ∼5× increase in the EQE at 850 nm by introducing the PTMH into the device. The enhancement in the EQE is evenly distributed across the entire wavelength range (640-1100 nm). The EQE of the devices without PTMH (flat devices) undergo a notable oscillation caused by the resonance at specific wavelengths and show a strong dependency on the angle of incidence. This characteristic dependency is significantly circumvented by introducing the PTMH into the APD. The devices exhibit a significantly low off-state power consumption of 0.41 μW/mm2 and stand fairly well against the state-of-the-art literature. Such high efficiency, low leakage, low breakdown voltage, and extremely low-power Si-APD can be easily incorporated into the existing CMOS foundry line and enable on-chip, high-speed, and low-photon count detection on a large scale