The Journal of Undergraduate Research at the University of Illinois at Chicago最新文献_第6页

Site-Directed Mutagenesis of N5-Carboxyaminoimidazole Ribonucleotide Mutase (Class I PurE) in Bacillus anthracis n5 -羧基氨基咪唑核糖核苷酸突变酶(Class I PurE)在炭疽芽孢杆菌中的定点突变

The Journal of Undergraduate Research at the University of Illinois at Chicago Pub Date : 2011-12-31 DOI: 10.5210/JUR.V5I1.7507

M. Silas, N. Wolf, L. Fung

{"title":"Site-Directed Mutagenesis of N5-Carboxyaminoimidazole Ribonucleotide Mutase (Class I PurE) in Bacillus anthracis","authors":"M. Silas, N. Wolf, L. Fung","doi":"10.5210/JUR.V5I1.7507","DOIUrl":"https://doi.org/10.5210/JUR.V5I1.7507","url":null,"abstract":"Anthrax, the infection caused by the Gram-positive pathogen Bacillus anthracis ( B. anthracis ), is fatal if untreated, and some strains of B. anthracis have been found to be resistant to currently available antibiotics. The development of broad spectrum antibiotics is needed to treat the resistive strains. In antibiotic development, we have targeted B. anthracis Class I PurE enzyme ( Ba PurE) as a unique and necessary enzyme in the de novo purine biosynthesis pathway, since the inactivation of this gene prevents B. anthraci growth in human serum, resulting in decreased bacterial proliferation. To identify inhibitors to $Ba$PurE, structural information on the substrate binding to its active site is needed. However, it is difficult to obtain crystals of Ba PurE with the substrate molecule in its binding site since upon binding to PurE, the substrate molecule is converted to the product molecule. An alternative approach is to create mutants of PurE that exhibit no enzymatic activity and do not convert the substrate to product, but still allow the substrate to bind to the active site. Then, the structure of mutant PurE with bound substrate can be obtained. We have identified a histidine residue at position 70 as the target of mutation to give an inactive enzyme. After successfully preparing the recombinant protein H70N, we have found that it exhibited no enzyme activity. This mutant will be useful in future experimentation to identify inhibitors of Ba PurE.","PeriodicalId":426348,"journal":{"name":"The Journal of Undergraduate Research at the University of Illinois at Chicago","volume":"306 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123316323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Characterization of Thermoelectric Ca3Co4O9 Microstructure Using Transmission Electron Microscopy 热电Ca3Co4O9微观结构的透射电镜表征

The Journal of Undergraduate Research at the University of Illinois at Chicago Pub Date : 2011-05-16 DOI: 10.5210/JUR.V5I1.7511

T. Paulauskas, R. Klie

引用次数: 3

The Dependence of Sample Thickness on Annular Bright Field Microscopy 样品厚度对环形亮场显微镜的依赖性

The Journal of Undergraduate Research at the University of Illinois at Chicago Pub Date : 2011-05-10 DOI: 10.5210/JUR.V5I1.7510

Misty Latting, W. Walkosz, R. Klie

{"title":"The Dependence of Sample Thickness on Annular Bright Field Microscopy","authors":"Misty Latting, W. Walkosz, R. Klie","doi":"10.5210/JUR.V5I1.7510","DOIUrl":"https://doi.org/10.5210/JUR.V5I1.7510","url":null,"abstract":"Annular Bright Field (ABF) is a relatively new method of Scanning Transmission Electron Microscopy (STEM) imaging that is desirable because of its ability to provide additional visual information in terms of showing lightweight atoms, whereas standard dark field imaging does not. In order to better understand the parameters necessary to perfect this method, this research article aimed to study a specific property of this imaging method: the dependence of sample thickness on image quality and atomic resolution. Multislice calculations were utilized to generate atomic potentials that were used to simulate different thicknesses of β-Si 3 N 4 . The resulting images were then examined to measure atomic full width at half-maximum (FWHM) in order to have a quantifiable value to support visual selection of the best ABF output image. Comparison of image quality/atomic resolution and FWHM values suggested that as a general trend, as sample thickness increases, atomic resolution and image quality deteriorate, citing Huygens' Principle of Classical Optics via the propagation of spherical electron waves through a vacuum. This study will bring a new awareness to the necessary precision required by researchers' sample preparation during Annular Bright Field imaging to yield the best image of their respective samples.","PeriodicalId":426348,"journal":{"name":"The Journal of Undergraduate Research at the University of Illinois at Chicago","volume":"24 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116587125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Characterization of Nickel Assisted Growth of Boron Nanostructures 镍辅助硼纳米结构生长的表征

The Journal of Undergraduate Research at the University of Illinois at Chicago Pub Date : 2010-12-29 DOI: 10.5210/JUR.V4I1.7486

F. Lagunas, B. Sorenson, P. Jash, M. Trenary

{"title":"Characterization of Nickel Assisted Growth of Boron Nanostructures","authors":"F. Lagunas, B. Sorenson, P. Jash, M. Trenary","doi":"10.5210/JUR.V4I1.7486","DOIUrl":"https://doi.org/10.5210/JUR.V4I1.7486","url":null,"abstract":"Boron nanostructures were synthesized by the vapor-liquid-solid mechanism using nickel as a catalyst. Two types of catalyst deposition methods were used: thermal evaporation and solution dispersion of Ni nanopowder. Also, the effect of synthesis temperature on the shapes of the nanostrucrure formed is reported here. The nanostructures were primarily characterized by Scanning Electron Microscopy (SEM). Further qualitative analyses were done with Transmission Electron Microscopy (TEM) and High Resolution Transmission Electron Microscopy (HRTEM). For quantitative analyses Energy Dispersive X-ray spectroscopy (EDX) and Electron Energy Loss Spectroscopy (EELS) were used. These results confirmed that 1) high purity Ni assisted boron nanostructures grow by pyrolysis of diborane, and that 2) oxide assisted growth of the nanostructures did not take place as carbon and oxygen were present only as surface contamination. Selected Area Electron Diffraction (SAED) patterns showed that the nanostructures were mainly crystalline. By decreasing the amount of nickel catalyst that is deposited by thermal evaporation the diameters of the nanowires were reduced. Also, the use of nickel nanopowder as catalyst instead of Ni film resulted in significant reduction in wire diameter. The diameter of the boron nanowires are about 36 nm. With nanowires other types of nanostructures were formed in either type of deposition. At the lower reaction temperature formation of nanosheets was observed.","PeriodicalId":426348,"journal":{"name":"The Journal of Undergraduate Research at the University of Illinois at Chicago","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132302164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Selective Atomic Layer Deposition (SALD) of Titanium Dioxide on Silicon and Copper Patterned Substrates 二氧化钛在硅和铜图案衬底上的选择性原子层沉积(SALD)

The Journal of Undergraduate Research at the University of Illinois at Chicago Pub Date : 2010-12-29 DOI: 10.5210/JUR.V4I1.7481

K. Overhage, Q. Tao, G. Jursich, C. Takoudis

引用次数: 3

Hydrodynamics of Drop Impact and Spray Cooling through Nanofiber Mats 纳米纤维垫的水滴冲击和喷雾冷却流体动力学研究

The Journal of Undergraduate Research at the University of Illinois at Chicago Pub Date : 2010-12-29 DOI: 10.5210/JUR.V4I1.7484

Y. Chan, F. Charbel, S. S. Ray, A. Yarin

引用次数: 1

Solvent Selection and Recycling for Carbon Absorption in a Pulverized Coal Power Plant 某煤粉电厂吸碳溶剂的选择与回收

The Journal of Undergraduate Research at the University of Illinois at Chicago Pub Date : 2010-12-29 DOI: 10.5210/JUR.V4I1.7482

R. Reed, P. Kotechs, U. Diwekar

引用次数: 0

Comprehensive JP8 Mechanism for Vitiated Flows 污浊流动的综合JP8机制

The Journal of Undergraduate Research at the University of Illinois at Chicago Pub Date : 2010-11-17 DOI: 10.5210/JUR.V4I1.7479

K. Hall, Xiao Fu, K. Brezinsky

引用次数: 0

Localized and Automated Chemical and Oxygen Delivery System for Microfluidic Brain Slice Devices 用于微流控脑切片装置的本地化和自动化化学和氧气输送系统

The Journal of Undergraduate Research at the University of Illinois at Chicago Pub Date : 2010-11-15 DOI: 10.5210/JUR.V4I1.7477

G. Yu, A. Blake, D. Eddington

引用次数: 2

The Design and Preparation of a Model Spectrin Protein: βII-Spectrin L2079P 模型Spectrin蛋白βII-Spectrin L2079P的设计与制备

The Journal of Undergraduate Research at the University of Illinois at Chicago Pub Date : 2010-11-15 DOI: 10.5210/JUR.V4I1.7475

N. Palmer, A. Antoniou, L. Fung

引用次数: 0