Development of masked silica tanning system for sustainable leather production.

Amid mounting pressure on the long-term recyclability of chromium in tanned leather and the associated environmental hazards, the quest for an alternative, cleaner tanning system has gained tremendous momentum. In this context, our study explores the remarkable potential of silicates as a versatile platform for skin/hide tanning, circumventing the inherent risks and ecological threats posed by chromium exposure and leaching. We present an alternative approach of using a silica-based tanning system, employing a Taguchi model, to optimize a masked silica (MaSil) tanning product/process for achieving effective collagen stabilization.

Impact of SiO nanoparticles on the structure and property of type I collagen in three different forms.

Silica-based nanoparticles have found application in the development of biocomposites involving reconstituted collagen in tissue engineering and wound healing, and leather modification, specifically targeting collagen fibers. However, a comprehensive investigation into the interaction between collagen-silica nanoparticles and different forms of collagen using biophysical methods remains unexplored. In this study, we examined the interaction between silica (SiO) nanoparticles and collagen in its fiber, microfibril, and monomer forms through high-resolution scanning electron microscopy, circular dichroism, Fourier-transform infrared spectroscopy, fluorescence analysis, zeta potential measurements, and turbidity assays.

Melamine-Based Polymeric Crosslinker for Cleaner Leather Production.

To augment sustainable tanning, less chrome input, high functional quality leather processed via no restricted substance in processing, and ease to treat the inevitable protein waste generated are the key challenge, and currently, they have become the active part of leather research. Our work covers the synthesis of a formaldehyde-free chromium-incorporated polymeric tanning agent (FF-CIPTA) and its application in a reformed leather processing route which ensures near zero discharge of chromium containing solid waste. The preliminary characterization of FF-CIPTA reveals that the developed product is stable up to pH 5.

Transvaginal ultrasound-guided direct thrombin injection for the treatment of intramyometrial pseudoaneurysm in a young female with uterine hemorrhage after failed uterine artery embolization.

Uterine artery pseudoaneurysm is an uncommon but important cause of severe uterine bleeding in the postpartum or postsurgical setting. The standard treatment options are endovascular uterine artery embolization and bilateral surgical internal iliac artery ligation for uterus conservation or hysterectomy. We report the case of a young female with hemorrhage from an intramyometrial pseudoaneurysm following repeated curettage and hysteroscopic excision of retained products of conception.

Induced apnea enhances image quality and visualization of cardiopulmonary anatomic during contrastenhanced cardiac computerized tomographic angiography in children.

Objective: The purpose of our study was to determine the effect of induced apnea on quality of cardiopulmonary structures during computerized tomographic (CT) angiography images in children with congenital heart diseases.

Methods: Pediatric patients with congenital heart defects undergoing cardiac CT angiography at our facility in the past 3 years participated in this study. The earlier patients underwent cardiac CT angiography without induced apnea and while, later, apnea was induced in patients, which was followed by electrocardiogram gated cardiac CT angiography.

Polarization selective, graded-reflectivity resonance filter, using a space-varying guided-mode resonance structure.

We designed, fabricated, and tested, polarization selective, graded-reflectivity resonant filters; based on a radial-gradient spatially-distributed, guided-mode resonance device architecture. The demonstrated filters have polarized spectral-resonance responses, distributed across their aperture extent, in the range between 1535 nm and 1540 nm wavelengths. Spectral sensitivity was observed on device tests, for wavelength changes as low as 0.

Spatial and spectral beam shaping with space-variant guided mode resonance filters.

Novel all-dielectric beam shaping elements were developed based on guided mode resonance (GMR) filters. This was achieved by spatially varying the duty cycle of a hexagonal-cell GMR filter, to locally detune from the resonant condition, which resulted in modified wavelength dependent reflection and transmission profiles, across the device aperture. This paper presents the design, fabrication, and characterization of the device and compares simulations to experimental results.

Design and optimization of space-variant photonic crystal filters.

A space-variant photonic crystal filter is designed and optimized that may be placed over a detector array to perform filtering functions tuned for each pixel. The photonic crystal is formed by etching arrays of holes through a multilayer stack of alternating high and low refractive index materials. Position of a narrow transmission notch within a wide reflection band is varied across the device aperture by adjusting the diameter of the holes.

Spatially polarizing autocloned elements.

A space-variant polarization converting element is introduced that utilizes an autocloning effect to produce high aspect ratio from birefringent gratings. This method utilizes a multilayer deposition process on a template to convert a linearly polarized incident beam to an azimuthally polarized output at a wavelength of 1.55 microm with more than 90% efficiency.

Micromachined arrays of cantilevered glass probes.

We describe the fabrication and characterization of cantilevered glass probe arrays. Individual probes have tapered shafts that are 175 microm square at the base and 200 nm square at the pyramidal tip. Each array contains as many as eight probes 10-20 mm long at 450-microm center-to-center spacing, fabricated from a single glass wafer by a combination of dicing and chemical etching.