Regulation of gastric acid secretion in situ by an endogenous activator protein: Studies with activator-specific antibody

Monospecific polyclonal antibody was raised against a homogenous preparation of endogenous activator protein (HAF) for the gastric H+,K+-ATPase system. Antibody was used to assess the regulatory role of the HAF in gastric acid secretion by isolated rabbit glands in situ. Immunohistochemical studies revealed aredistribution of theHAFtowards discrete intracellular zones following stimulation of the glands with histamine. The antibody, when inserted into the stimulated gastric glands by digitonin permeabilization, could effectively block the acid forming ability of the cells. The data offers, for the first time, some concrete in situ evidence for the role of the HAF as an intracellular regulator of gastric H+ transport .The manuscript was written (in the early 1990) soon after the data were collected, but never submitted to a journal with the hope of getting better gel picture and fluorescent micrograph which did not materialize due to unavoidable circumstances

Hydrogen Storage in Nano-Phase Diamond at High Temperature and Its Release

The objectives of this proposed research were: 91) Separation and storage of hydrogen on nanophase diamonds. It is expected that the produced hydrogen, which will be in a mixture, can be directed to a nanophase diamond system directly, which will not only store the hydrogen, but also separate it from the gas mixture, and (2) release of the stored hydrogen from the nanophase diamond

Development and Evaluation of an Order-N Formulation for Multi-Flexible Body Space Systems

This paper presents development of a generic recursive Order-N algorithm for systems with rigid and flexible bodies, in tree or closed-loop topology, with N being the number of bodies of the system. Simulation results are presented for several test cases to verify and evaluate the performance of the code compared to an existing efficient dense mass matrix-based code. The comparison brought out situations where Order-N or mass matrix-based algorithms could be useful

Production of nano particles

Abstract only availableNano particles (particles having diameters in the nanometer range) have applications in a variety of areas including medical, environmental, sensor, to name a few. However, the production of nano particles having uniform size and properties is challenging. A number of methods have been proposed for production of nano particles such as flame synthesis, aersol decomposition using indirect heating, and laser ablation. In this work we used a flame synthesis process to produce nano particles of aluminum oxide (Al2O3). Aluminum oxide is used in ceramic industry. The nano size particles can change various mechanical and physical properties of Al2O3 based materials significantly. Two different precursor salts were used for production of Al2O3. The first one was aluminum nitrate-nano hydrate (Al(NO3)3*9H2O) of different concentrations and the other one was aluminum acetate basic (C2H3O2)2AlOH. An aqueous solution of these salts flowed through a mini-mist nozzle and the resulting spray was decomposed in a methane-air flame to produce the particles. Different concentrations of aluminum nitrate and nozzle sizes were used to investigate their effect on the particle size. The particles were analyzed using a scanning electron microscopy (SEM) that showed particles with different sizes, shape and having a porous surface. Although particles in the nano size range were produced, some particles were also in the micron size range. The precursor salt also had significant effect on the particle morphology.Nuclear Science and Engineering Institute (NSEI

Unbiasing Enhanced Sampling on a High-dimensional Free Energy Surface with Deep Generative Model

Biased enhanced sampling methods utilizing collective variables (CVs) are powerful tools for sampling conformational ensembles. Due to high intrinsic dimensions, efficiently generating conformational ensembles for complex systems requires enhanced sampling on high-dimensional free energy surfaces. While methods like temperature-accelerated molecular dynamics (TAMD) can adopt many CVs in a simulation, unbiasing the simulation requires accurate modeling of a high-dimensional CV probability distribution, which is challenging for traditional density estimation techniques. Here we propose an unbiasing method based on the score-based diffusion model, a deep generative learning method that excels in density estimation across complex data landscapes. We test the score-based diffusion unbiasing method on TAMD simulations. The results demonstrate that this unbiasing approach significantly outperforms traditional unbiasing methods, and can generate accurate unbiased conformational ensembles for simulations with a number of CVs higher than usual ranges

Preparation of chitosan beads and membranes for industrial applications [abstract]

Faculty Mentor: Dr. Tushar K. Gosh, Nuclear Science and Engineering Instite (NSEI)Abstract only availableIndustrial waste water contains a variety of toxic chemicals including toxic heavy metals that must be removed before discharging to the environment. A number of methods have been investigated to remove these heavy metals. The use of chitosan for removal of some of these toxic metals appears to be very promising. Chitosan is a natural product derived from chitin, a polysaccharide found in the exoskeleton of shellfish like shrimp or crabs. The term Chitosan does not refers to a uniquely defined compound; it merely refers to a family of copolymers with various fractions of acetylated units. Chitosan in its natural form is not suitable for industrial application. In this study, chitosan was modified and prepared as beads so that it can be easily used for various applications. Chitosan Beads were prepared under various conditions. Commercially available chitosan flakes were dissolved in either acetic acid or oxalic acid and a homogeneous mixture was prepared. The spherical beads were obtained by drop wise addition of the acidic mixture into a NaOH bath. The beads were washed with distilled water until the pH was neutral or 7. Beads were then dried either in a vacuum oven or by freeze drying. Theses beads can be used to remove metals and other contaminants from the ground and waste waters. Attempts were also made to prepare chitosan membrane that can have application in Fuel Cells. The beads were characterized by scanning electron microscope and were also evaluated for chromium (III) adsorption

An Efficient Solution Method for Multibody Systems with Loops Using Multiple Processors

This paper describes a multibody dynamics algorithm formulated for parallel implementation on multiprocessor computing platforms using the divide-and-conquer approach. The system of interest is a general topology of rigid and elastic articulated bodies with or without loops. The algorithm divides the multibody system into a number of smaller sets of bodies in chain or tree structures, called "branches" at convenient joints called "connection points", and uses an Order-N (O (N)) approach to formulate the dynamics of each branch in terms of the unknown spatial connection forces. The equations of motion for the branches, leaving the connection forces as unknowns, are implemented in separate processors in parallel for computational efficiency, and the equations for all the unknown connection forces are synthesized and solved in one or several processors. The performances of two implementations of this divide-and-conquer algorithm in multiple processors are compared with an existing method implemented on a single processor

Mode Selection Techniques in Variable Mass Flexible Body Modeling

In developing a flexible body spacecraft simulation for the Launch Abort System of the Orion vehicle, when a rapid mass depletion takes place, the dynamics problem with time varying eigenmodes had to be addressed. Three different techniques were implemented, with different trade-offs made between performance and fidelity. A number of technical issues had to be solved in the process. This paper covers the background of the variable mass flexibility problem, the three approaches to simulating it, and the technical issues that were solved in formulating and implementing them