Sub-Picogram, Inline Detection Of Proteins Using Microfluidic Drop Generators And Shape-Based Detection

Proteomic workflows rely on sensitive and precise methods for purifying and detecting proteins, and one of the most popular methods is liquid chromatography (LC) followed by an inline detector. However, the most commonly used method, UV-Vis absorbance, provides relatively low sensitivity and requires long path lengths in the flow cell. In this thesis, we present a highly sensitive, label-free method to detect proteins in continuous flow, using a pressure-driven microfluidic droplet generator. The system consists of a cross junction or flow focusing structure where the flowing stream of proteins is combined with two coflowing streams of oil which break up the former stream into a train of droplets. In such a system, the droplet size predictably scales with interfacial tension (IFT) of the oil-water interface. When globular proteins (eg BSA) enter the junction, they adsorb to the interface and reduce IFT, and thereby the droplet radius. Temporal variations in droplet size therefore correlate with changes in protein concentration. Using microfluidic drop generators as an inline detection method provides two benefits: 1) it can improve available limits of detection, because the high surface area to volume ratio enhances adsorption phenomena, and 2) it provides fast time resolution, due to the high rate of drop generation. Four different carrier phases (oleic acid, octanol, hexadecane, and FC-40) were tested with four proteins (BSA, thyroglobulin, uridine, placental growth factor, galectin and blood plasma). Droplet sizes were found to decrease when a hydrophobic protein was combined with a hydrophobic carrier. The best limit of detection is ~1 μg/mL in a 1 nL droplet, which equates to 1 fg of total protein. The low detection limits are due to favorable scaling: the high surface area to volume ratio in droplet systems increases the probability of adsorption, and therefore changes drop size even at low concentration. When used as a detector for high performance liquid chromatography (HPLC), it demonstrates sensitivity up to 100X better than conventional UV-Vis detectors. This detection method can potentially serve as a label-free, universal detector for proteins

The Distance Between Principle and Practice in the Obama Administration\u27s Targeted Killing Program: A Response to Jeh Johnson

On December 17, 2009, a U.S. cruise missile struck a village in southern Yemen, killing forty-one members of two families-half of whom were children, ages one to fifteen. The target was an alleged al Qaeda-affiliated training camp in the same region, but according to the Yemeni parliamentary committee that investigated the strike, there were errors in the geographic coordinates and the determination of the location. The United States initially refused to comment, while Yemeni authorities claimed that it had been their own fighter jets that had killed dozens of militants in simultaneous operations. Nearly a year after the strike, however, the media reported government cables obtained by Wikileaks that made the United States\u27 role clear: during a conversation between former CIA Director David Petraeus and then-Yemeni President Ali Abdullah Saleh, the Yemeni leader assured Petraeus that the Yemenis would continue saying the bombs are ours, not yours

Mesenchymal Stem Cell Therapy in the Treatment of Acute and Chronic Graft Versus Host Disease

Mesenchymal stem cells (MSC) are a cellular component of the supportive microenvironment (stroma) found in the bone marrow, umbilical cord, placenta, and adipose tissues. In addition to providing cellular and extracellular cues to support the proliferation and differentiation of cells that comprise functional tissues, MSC also contribute to tissue repair and have immunomodulatory properties. Their ability to modulate immunologic reactions while themselves not provoking immunologic responses from alloreactive T-lymphocytes and/or other effector cells, make MSC a potentially ideal therapeutic agent with which to treat graft versus host disease (GvHD) following hematopoietic transplantation. Despite in vitro experiments confirming that MSC suppress mixed lymphocyte reactions (MLR) and in vivo evidence from mouse models that show evidence that MSC can ameliorate GvHD, clinical trials to date using MSC to treat GvHD have shown mixed results. Whether this is a consequence of suboptimal timing and dose of administered MSC remains to be clarified. It is clear that immunomodulatory potential of MSC as a cellular therapy for GvHD remains to be realized in the clinic

Generalized Wardrop Equilibrium for Charging Station Selection and Route Choice of Electric Vehicles in Joint Power Distribution and Transportation Networks

This paper presents the equilibrium analysis of a game composed of heterogeneous electric vehicles (EVs) and a power distribution system operator (DSO) as the players, and charging station operators (CSOs) and a transportation network operator (TNO) as coordinators. Each EV tries to pick a charging station as its destination and a route to get there at the same time. However, the traffic and electrical load congestion on the roads and charging stations lead to the interdependencies between the optimal decisions of EVs. CSOs and the TNO need to apply some tolling to control such congestion. On the other hand, the pricing at charging stations depends on real-time distributional locational marginal pricing, which is determined by the DSO after solving the optimal power flow over the power distribution network. This paper also takes into account the local and the coupling/infrastructure constraints of EVs, transportation and distribution networks. This problem is modeled as a generalized aggregative game, and then a decentralized learning method is proposed to obtain an equilibrium point of the game, which is known as variational generalized Wardrop equilibrium. The existence of such an equilibrium point and the convergence of the proposed algorithm to it are proven. We undertake numerical studies on the Savannah city model and the IEEE 33-bus distribution network and investigate the impact of various characteristics on demand and prices

Дискретная структура катодного пятна и токопроводящего канала электрической дуги

На основе анализа известных экспериментальных фактов показано, что при возбуждении электрической дуги в результате автоэлектронной эмиссии возникает ток, который течет через ячейки - микронеровности катода. Выгорание катода происходит по микронеровностям, при этом образуются кратеры на поверхности катода. Данное явление служит причиной дискретной (ячеистой) структуры катода. Установлено, что в результате стекания электронов с микронеровностей образуются тонкие токовые каналы, замыкающие цепь анод-катод электрической дуги. Сделан вывод о том, что токопроводящий канал электрической дуги имеет дискретное строение и представляет собой совокупность тонких каналов, через которые течет основной ток разряда

Study on the conflicts between work and family at the Kashan University of Medical Sciences, Iran

With both professional and personal responsibilities, employees often conflict when reconciling the demands of family and work. The study aimed to investigate whether work to family conflict experienced by employees of Kashan University of medical sciences differed from family to work conflict.A cross sectional study was carried out in 2014. A random sample of 202 employees in the four schools affiliated with Kashan University of medical sciences located in central of Iran was selected and responded to items of the questionnaires using a 7-point Likert scale. Work-family conflict was measured using Carlson et al.'s 18 items scale. Higher values indicate higher levels of work to family conflict and family to work conflict. Analysis was carried out using SPSS 16.Employees experienced work-family conflict in the two directions. Work to family conflict with mean of 31.5510.68 was significantly (t=9.87, P<0.001) more than family to work conflict with 25.588.77. They experienced different time-, strain-, and behavior-based work to family conflicts than time-, strain-, and behavior-based family to work conflicts (P<0.01).Work to family conflict was more than family to work conflict. Therefore, University authorities should try to improve working conditions through changing the working culture and re-looking into their work structure and employment policies to moderate the experience of work to family conflicts encountered by the employees

Influence of psychological empowerment on organizational commitment among medical employees in a hospital setting

Introduction: people within organizations are a key factor for efficiency. Thus employee empowerment has become a popular management strategy. The study aimed to investigate the relationship between psychological empowerment and organizational commitment among medical staff of a hospital in Zahedan city. Methods: This cross sectional study was carried out in 2013. A random sample of 172 medical employees in Khatam-ol-Anbia hospital at Zahedan city was selected and responded to items of the questionnaires using a 7-point Likert scale ranging from 1 to 7. For measuring psychological empowerment and organizational commitment, Mishra & Spreitzer's scale and Meyer and Allen's questionnaire were used. A higher score means a higher degree of psychological empowerment or organizational commitment. Analysis was carried out using SPSS. Results: The level of organizational commitment and psychological empowerment significantly were higher than average. There was a significant positive relationship between employees' empowerment and their commitment to organization. Psychological empowerment was a significant predictor of organizational commitment (β = .524). Out of the five dimensions of empowerment three dimensions are significant predictors of commitment and explain 37,1% of the variance in commitment. Conclusions: Due to The positive influence of psychological empowerment on organizational commitment, programs for in-service education should focus on facilitating psychological empowerment to improve and increase organizational commitment. Also, since impact of employees psychological empowerment on organizational commitment partially supported, there are other variables that influence the organizational commitment

Inactivation of tumor suppressor genes and cancer therapy : an evolutionary game theory approach

Inactivation of alleles in tumor suppressor genes (TSG) is one of the important issues resulting in evolution of cancerous cells. In this paper, the evolution of healthy, one and two missed allele cells is modeled using the concept of evolutionary game theory and replicator dynamics. The proposed model also takes into account the interaction rates of the cells as designing parameters of the system. Different combinations of the equilibrium points of the parameterized nonlinear system is studied and categorized into some cases. In each case, the interaction rates’ values are suggested in a way that the equilibrium points of the replicator dynamics are located on an appropriate region of the state space. Based on the suggested interaction rates, it is proved that the system doesn't have any undesirable interior equilibrium point as well. Therefore, the system will converge to the desirable region, where there is a scanty level of cancerous cells. In addition, the proposed conditions for interaction rates guarantee that, when a trajectory of the system reaches the boundaries, then it will stay there forever which is a desirable property since the equilibrium points have been already located on the boundaries, appropriately. The simulation results show the effectiveness of the suggestions in the elimination of the cancerous cells in different scenarios