Pressure-assisted densification was used
by way of a hot press to optimize the
conditions of heat and pressure when
applied to anatase (TiO2). This study
optimized hot-pressing conditions, which
will be helpful when doping TiO2 because it
will allow optimization of bulk anatase for
transparent conductive oxide (TCO)
applications. Lessons...
A self-assembled monolayer of an alkene or
alkyne can be applied to a hydrogenpassivated
silicon surface using UV hydrosilylation.
This research shows that
field-induced oxides can be used as a
negative resist to selectively prevent
bromostyrene attachment, providing a
means of nanopatterning organic molecules
on silicon. The negative resist effects...
Numerous studies have been structured to
investigate magnetoelectric multiferroic
materials, which possess simultaneous
ferroelectric and (anti)ferromagnetic
ordering. Bismuth ferrite (BiFeO3), referred
to as BFO, has drawn special attention
because of its unique ability to maintain both
electric and magnetic dipole moments at
room temperature. BFO shows great
potential to revolutionize...
When the Aß peptides aggregate into
soluble oligomeric clusters, they form
central nervous system neurotoxins known
as amyloid-ß-derived diffusible ligands
(ADDLs). The assembly of ADDLs is
currently thought to be a pathogenic
process in Alzheimer's disease (AD).
Understanding the molecular structure and
properties of ADDLs could prove useful in
the...
Silver nanoparticles exhibit distinctive
optical properties. When exposed to
electromagnetic radiation, a noble metal
nanoparticle demonstrates the unique
optical property of localized surface
plasmon resonance (LSPR). LSPR is
measured through an extinction spectrum,
the sum of absorption and Rayleigh
scattering, which results when the
collective oscillation of electrons is
resonant...
In many biological systems, ligand-receptor
pairs bind to each other via noncovalent
interactions such as hydrogen-bonding and
Van der Waals forces. This project’s method
of studying these interactions uses electron
transfer theory. When a receptor binds to a
redox-modified ligand, there is a change in
the reorganization energy of the...
Germanium (Ge) nanowires were grown via
the vapor-liquid-solid growth mechanism
and surface-doped with manganese (Mn).
The nanowires were annealed at 350˚ C for
30 min to promote the Mn diffusion.
Pulsed-laser local electrode atom probe
tomography was used to determine the
concentration and distribution of Mn in the
Ge nanowires....
In this research project, particle sorting of
Brownian liquids was explored by sweeping
two noncoherent pairs of parallel optical
standing waves in a translating medium.
Each wave was created by interfering two
coherent beams of light, and the resulting
fringe periods were determined by the angle
of intersection. Adjusting the...
Chip-based devices and biosensors
incorporate the attachment of biomolecules
at interfaces. The behavior of biomolecules
at the surface and interfaces differs from the
behavior of biomolecules in the bulk solution.
Surface-analysis techniques are therefore
required to characterize these interfaces.
Second harmonic generation (SHG) has been
used to characterize DNA on...
Concern about maximizing and improving heterogeneous catalysis has
grown because it is used in a variety of applications. This study focused
on the effect single-walled carbon nanotubes (SWNTs) had on titanium
dioxide (TiO2) catalysis. Two different forms of TiO2, rutile and anatase,
were combined with SWNTs in heterogeneous mixtures and...
Semiconductor oxides are important materials in gas-detection systems
and can be improved by enhancing the sensitivity and selectivity of
oxide sensors to specific gases. This research investigates the effect of
palladium dopant (Pd) on the hydrogen gas-sensing ability of ZnO 2-D
nanostructures. Photolithography was used to pattern electrodes on
various...
The aim of this research is to investigate the pH effect on the assembled
nanostructures of peptide amphiphiles (PAs). Controlling the sizes and
shapes of these assembled nanostructures is of great importance for
their ultimate applications in drug delivery, tissue engineering, and
regenerative medicine. A complete characterization of these nanostructures...
Bone-related problems have always been a concern in the medical field,
particularly how to heal and rebuild bones more rapidly when injuries
occur. A path to solving such problems might be to examine the
processes when bone develops in nature. This project aims at discovering
the chemical reactions that occur...
The formation of covalently grafted polymer brushes on silica (SiO2)
nanoparticles was achieved by surface-initiated reversible additionfragmentation
chain transfer (si-RAFT) polymerization. RAFT initiator
was first attached onto the surface of silica nanoparticles and then
examined by ultraviolet-visible spectroscopy (UV-vis) analysis. From the
resulting RAFT initiator-modified SiO2 nanoparticles, polymer chains
can...
Polymer nanoparticles (PNPs) were formed from amphiphilic diblock
copolymers consisting of a hydrophilic block with pendant polyethylene
glycol tosylate (PEG-OTs) groups and a hydrophobic block with pendant
terthiophene (TTT) groups. The resulting PNPs were characterized
using dynamic light scattering (DLS) and transmission electron
microscopy (TEM) to determine size, shape, and...
The formation of organic layers on hydrogen-passivated silicon (HPS)
surfaces via (UV) ultraviolet treatment was completed for three styrene
derivatives with different conjugated lengths. The styrene molecules
were synthesized and characterized using nuclear magnetic resonance
(NMR) spectroscopy and gas chromatography-mass spectrometry
(GC-MS). Layer formation on silicon was then accomplished through...
In the field of clinical diagnostics, biosensors are used to identify genetic
disorders by hybridizing a surface-bound DNA sequence with the
patient’s DNA. To further improve biosensor design, two nonlinear
optical techniques, sum frequency generation (SFG) and second
harmonic generation (SHG), were used to probe the orientation,
chirality, and surface...
Small, soluble, self-assembling peptide Aβ-oligomers, known as ADDLs
(amyloid-derived diffusible ligands), accumulate in the Alzheimer’s
disease (AD) brain as Aβ 12-mers and are thought to contribute to AD
neuropathological conditions. Unlike plaques, which were once thought
to cause neuronal death due to insoluble amyloid plaque deposits,
ADDLs initiate abnormal changes...
Semiconductor nanowires show promise for application in nanoscale
electronics, but the difficulty of forming low-resistance ohmic contacts
provides a challenge to their implementation. To improve the electrical
performance of lithographically defined nickel contacts, nickel-silicide/
silicon axial nanowire heterostructures were formed by controlled
partial silicidation. Prior to annealing, two-terminal silicon nanowire...
Small, soluble, self-assembling peptide Aβ-oligomers, known as ADDLs
(amyloid-derived diffusible ligands), accumulate in the Alzheimer’s
disease (AD) brain as Aβ 12-mers and are thought to contribute to AD
neuropathological conditions. Unlike plaques, which were once thought
to cause neuronal death due to insoluble amyloid plaque deposits,
ADDLs initiate abnormal changes...
"This paper describes the development of an efficient transfection
vehicle for nucleic acids using surface-functionalized gold nanoparticles
(AuNPs) with a mixed-monolayer of biological molecules—a hybrid
approach that combines two previously investigated models. The
objective is to improve upon previously described nanoparticles used to
introduce nucleic acids to cells—oligonucleotide-functionalized AuNPs
and...
This paper reports the syntheses of acetylene-terminated smallmolecule
cores. Also reported are successful attempts at “click”
coupling the core molecules with azide-terminated oligonucleotides to
construct stable small-molecule DNA hybrids (SMDH). Once these
click-based small-molecule DNA hybrids are formed, melting studies
will be done that study how the geometry of SMDH...
The swelling and deswelling behavior of poly(methacrylic acid) (PMAA)
thin films and the permeability of poly(styrene) (PS) membranes was
investigated using quartz crystal microbalance and ellipsometry.
The system consisted of either homopolymer PMAA film or diblock
poly(methyl methacrylate)-poly(methacrylic acid) (PMMA-PMAA)
brushes with a hydrophobic PS membrane capping layer. Results show...
This study examined the invasiveness of nanofountain probes (NFP)
when used as a transfection tool for single-cell research. For comparison,
the damage caused to cells by more commonly used commercial
atomic force microscope (AFM) probes was also studied. Forces were
applied to cells at increasing levels using both probes, and...
Cadmium selenide (CdSe) quantum dots have low conductivity upon
synthesis with the original capping ligands. The conductivity can be
altered by the addition of other ligands. Thiols, amines, and carboxylic
acids, as well as other functional groups, have been shown to improve
conductivity in quantum dot films. This investigation describes...
This paper investigates the use of self-assembled monolayers
(SAMs) to optimize the localized surface plasmon resonance (LSPR)
biosensor for disease detection. Various experiments were done
with 1-(9-mercaptononyl)-3,6,9-trioxaundecan-11-ol (TDT) and
heptaoxatricosanoic acid (HSA), a new SAM; these included a solvent
study to determine refractive index sensitivity and nonspecific binding
and specific...
Under the correct conditions, aluminum can be anodized in an electrochemical
cell to produce hexagonally ordered arrays of nanoscale
pores. This study examines how adding the chemicals methanol and
acetic acid to a typical anodization solution alters pore-growth patterns
across the surface oxide layer. The existence of the unique pore-growth...
Thermoelectric materials, which convert heat energy to electrical
energy, may become increasingly important in the world’s energy
situation. Through the inclusion of nanoscale features embedded within
a thermoelectric bulk material, it has been shown that a corresponding
decrease in lattice thermal conductivity results in an enhanced
thermoelectric figure of merit,...
Alzheimer’s disease (AD) is one of the most common forms of dementia,
with no current definitive premortem diagnosis. Amyloid beta-peptide
derived diffusible ligands, known as ADDLs, have become a key link in
the AD specificity for memory loss and are a potential biomarker for AD.
In order to develop an...
Neurons are difficult to manipulate experimentally. Most transfection
reagents used for gene silencing are neurotoxic, and the postmitotic
state of neurons prevents the effective use of viral vectors. This study
demonstrated the delivery of antisense DNA against target genes by
gold nanoparticle oligonucleotide complexes (GNOs) in primary cultures
of rat...
Magnetic nanostructures (MNS) have become the subject of intense
interest due to their superparamagnetic properties and consequently
their potential uses in medical diagnostics and therapeutics. In this
study, monodisperse magnetite MNSs were synthesized via thermal
decomposition of iron(III) acetylacetonate and transferred to aqueous
solution using 11-aminoundecanoic acid as the surfactant....
With the advent of a variety of novel nanometer-scale diagnostic techniques such as DNA micro- and nanoarrays, increasing focus has been placed on developing methods to quickly and accurately create these nanometer scale patterns. One promising technique for depositing DNA, proteins, and other liquid molecular "inks" with submicron resolution is...
Welcome to the second issue of Politica Northwestern, the academic
journal of Northwestern University’s Politics & Policy (P&P). P&P analyzes
the world in terms of impactful events. Political events occur constantly,
but their impacts are by no means equal. We distill major events to
determine how they will change the...
This past week saw Germany hold federal elections for the Bundestag, the
national parliament. The center-right Christian Democrat Union (CDU)
gained 33% of the vote, essentially securing Angela Merkel’s fourth term
as chancellor. The Social Democrats (SPD) secured 20.5% votes, retaining
their position as the Bundestag’s second largest party. However,...
As American tech companies contend with strict scrutiny from Congress
in the wake of the 2016 election, several have already been harassed by
European regulators. During the past year, Amazon and Google were
slapped with massive fines, continuing a trend of EU hostility toward
major American tech companies.
The Republican party has for years sought to reform an American tax code
widely viewed as uncompetitive, expressing their ambitious goal as simply
making the tax system “that looks like someone designed it on purpose.”
Last November, when the party gained control of both chambers of
Congress and the White...
When watching this year’s Golden Globes, Grammy Awards and other
shows honoring the past year’s best in entertainment, it was hard to miss
the rows of matching dress. Behind the black attire and parade of white
roses, stretched the industry stood unified after the myriad allegations and
confessions that have...
One of the first official decisions that Donald Trump made after his
inauguration was to withdraw US support for the Trans-Pacific
Partnership (TPP). Mr Trump argued throughout the election that the
pact, and many other global trade deals, was harmful to American
companies and American workers and that he would...