11 research outputs found
Electrically Switchable Polymer Brushes for Protein Capture and Release in Biological Environments**
Interfaces functionalized with polymers are known for providing excellent resistance towards biomolecular adsorption and for their ability to bind high amounts of protein while preserving their structure. However, making an interface that switches between these two states has proven challenging and concepts to date rely on changes in the physiochemical environment, which is static in biological systems. Here we present the first interface that can be electrically switched between a high-capacity (>1 ÎŒg cmâ2) multilayer protein binding state and a completely non-fouling state (no detectable adsorption). Switching is possible over multiple cycles without any regeneration. Importantly, switching works even when the interface is in direct contact with biological fluids and a buffered environment. The technology offers many applications such as zero fouling on demand, patterning or separation of proteins as well as controlled release of biologics in a physiological environment, showing high potential for future drug delivery in vivo
Stable trapping of multiple proteins at physiological conditions using nanoscale chambers with macromolecular gates
The possibility to detect and analyze single or few biological molecules is very important for understanding interactions and reaction mechanisms. Ideally, the molecules should be confined to a nanoscale volume so that the observation time by optical methods can be extended. However, it has proven difficult to develop reliable, non-invasive trapping techniques for biomolecules under physiological conditions. Here we present a platform for long-term tether-free (solution phase) trapping of proteins without exposing them to any field gradient forces. We show that a responsive polymer brush can make solid state nanopores switch between a fully open and a fully closed state with respect to proteins, while always allowing the passage of solvent, ions and small molecules. This makes it possible to trap a very high number of proteins (500-1000) inside nanoscale chambers as small as one attoliter, reaching concentrations up to 60 gLâ1. Our method is fully compatible with parallelization by imaging arrays of nanochambers. Additionally, we show that enzymatic cascade reactions can be performed with multiple native enzymes under full nanoscale confinement and steady supply of reactants. This platform will greatly extend the possibilities to optically analyze interactions involving multiple proteins, such as the dynamics of oligomerization events
Software test effort estimation state of the art in Turkish software industry
Good planning and managing software test process require accurate estimation of software test effort. This becomes particularly significant when validation and verification activities are to be performed by an independent organization. This study presents a systematic literature review and a follow up industrial survey, which was performed to investigate the state of the art on software test effort estimation and the current practice of software industry in Turkey. The results showed that only few of the methods and metrics discussed in the literature are used by the industry. Furthermore, industrial participants have a general opinion that these methods could be improved by making use of additional metrics. Hence, there is a significant need for collaborative studies between industry and academia
Temperament and Character Dimensions of Personality in Patients with Generalized Anxiety Disorder
WOS: 000396634000002Temperament and character dimensions of personality in patients with generalized anxiety disorder Objective: It is known that a complex relationship is present between anxiety and personality. In this study, we aimed to compare the clinical features and personality traits of patients with GAD and healthy controls. We hypothesized that Harm Avoidance scores would be higher and predictive of GAD compared to the healthy controls. Methods: This study was conducted in outpatients with GAD who presented to the Bagcilar Training and Research Hospital's Outpatient Psychiatry Clinic. The sample was comprised of 40 outpatient (30 women, 10 men) who met Diagnostic and Statistical Manual of Mental Disorders -DSM-5 criteria for GAD, who were not under any medication treatments. The control group comprised of 40 healthy controls (23 women, 17 men). Semi-structured sociodemographic data form, Temperament and Character Inventory (TCI), General Anxiety Disorder Scale (GAD-7), Beck Depression Inventory (BDI), the Beck Anxiety Inventory (BAI), State-Trait Anxiety Inventory (STAI-I and II) were administered to the participants. All statistical analyses were performed using SPSS for Windows, Version 23.0. Results: Impulsiveness subscale of Novelty Seeking; Harm Avoidance and its subscales of Anticipatory worry, Fear of uncertainty, Shyness with strangers, and Fatigability and asthenia scores were significantly higher in GAD patients compared to the control group. Harm Avoidance and its subscales of Anticipatory worry, Fear of uncertainty, Shyness with strangers, and Fatigability and asthenia scores were significantly highly positively correlated with the BDI, BAI, STAI-I /STAI-II, and GAD-7 scores. When GAD-7 scores was entered as the dependent variable and age and gender were controlled in regression analysis, Harm Avoidance and its subscale of Shyness, Persistence, and Self-Transcendence were significantly predictive of GAD-7 scores. Conclusions: Temperament and character traits of the GAD patients were significantly different from the healthy control subjects. HA scores were higher and predictive of GAD compared to healthy controls
Temperament and Character Dimensions of Personality in Patients with Chronic Pain Disorders
Temperament and character dimensions of personality in patients with chronic pain disorders
Objective: It is known that a complex relationship is present between chronic pain and personality. In this study, we aimed to compare the clinical features and personality traits of patients with Chronic Pain Disorder (CPD) and healthy controls. We hypothesized that Harm Avoidance (HA) scores would be higher and predictive of compared to healthy controls.
Methods: This study was conducted in outpatients with CPD who presented to the Bagcilar Training and Research Hospital's Outpatient Psychiatry Clinic. The sample was comprised of 60 outpatients (53 women, 7 men) who complained of chronic pain for at least 3 months and were not under any medication treatments. The control group comprised of 60 healthy controls (49 women, 11 men). Semi-structured sociodemographic data form, Visual Analog Scale (VAS), Temperament and Character Inventory (TCI), Beck Depression Inventory (BDI), and the Beck Anxiety Inventory (BAI) were administered to the participants. All statistical analyses were performed using SPSS for Windows, Version 23.0.
Results: Impulsiveness subscale of Novelty Seeking; Harm Avoidance and its subscales of Anticipatory worry, Fear of uncertainty, Shyness with strangers, and Fatigability and asthenia scores were significantly higher in CPD patients compared to the control group. Harm Avoidance and its subscales of Anticipatory worry, Fear of uncertainty, Shyness with strangers, and Fatigability and asthenia scores were significantly positively correlated with the BDI, BAI, and VAS scores. When VAS scores were entered as the dependent variable and age and gender were controlled in regression analysis, Harm Avoidance was significantly predictive of VAS scores.
Conclusion: Temperament and character traits of the CPD patients were significantly different from the healthy control subjects. HA scores were higher and predictive of CPD compared to healthy controls
Generic High-Capacity Electrochemical Capture and Release of Proteins by Polyelectrolyte Brushes
We present a polyelectrolyte brush electrode with
high-capacity for protein immobilization that captures and releases proteins by
an electrochemical potential. Central to our concept is the use of
polyelectrolyte brushes that switch reversibly by electrochemistry. Our
electrode enables high-fidelity control of protein species in space and time.
We predict several application areas for this technology; for instance in
protein separation and in biomedical devices.</p
Software test effort estimation state of the art in Turkish software industry
Good planning and managing software test process require accurate estimation of software test effort. This becomes particularly significant when validation and verification activities are to be performed by an independent organization. This study presents a systematic literature review and a follow up industrial survey, which was performed to investigate the state of the art on software test effort estimation and the current practice of software industry in Turkey. The results showed that only few of the methods and metrics discussed in the literature are used by the industry. Furthermore, industrial participants have a general opinion that these methods could be improved by making use of additional metrics. Hence, there is a significant need for collaborative studies between industry and academia
Gating Protein Transport in Solid State Nanopores by Single Molecule Recognition
Control
of molecular translocation through nanoscale apertures
is of great interest for DNA sequencing, biomolecular filters, and
new platforms for single molecule analysis. However, methods for controlling
the permeability of nanopores are very limited. Here, we show how
nanopores functionalized with polyÂ(ethylene glycol) brushes, which
fully prevent protein translocation, can be reversibly gated to an
âopenâ state by binding of single IgG antibodies that
disrupt the macromolecular barrier. On the basis of surface plasmon
resonance data we propose a two-state model describing the antibodyâpolymer
interaction kinetics. Reversibly (weakly) bound antibodies decrease
the protein exclusion height while irreversibly (strongly) bound antibodies
do not. Our results are further supported by fluorescence readout
from pore arrays and high-speed atomic force microscopy on single
pores. This type of dynamic barrier control on the nanoscale provides
new possibilities for biomolecular separation and analysis
Gating Protein Transport in Solid State Nanopores by Single Molecule Recognition
Control
of molecular translocation through nanoscale apertures
is of great interest for DNA sequencing, biomolecular filters, and
new platforms for single molecule analysis. However, methods for controlling
the permeability of nanopores are very limited. Here, we show how
nanopores functionalized with polyÂ(ethylene glycol) brushes, which
fully prevent protein translocation, can be reversibly gated to an
âopenâ state by binding of single IgG antibodies that
disrupt the macromolecular barrier. On the basis of surface plasmon
resonance data we propose a two-state model describing the antibodyâpolymer
interaction kinetics. Reversibly (weakly) bound antibodies decrease
the protein exclusion height while irreversibly (strongly) bound antibodies
do not. Our results are further supported by fluorescence readout
from pore arrays and high-speed atomic force microscopy on single
pores. This type of dynamic barrier control on the nanoscale provides
new possibilities for biomolecular separation and analysis